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The effect of different c. difficile MLST strains on viability and activity of macrophages

HELIYON 2023年第3期9卷

作者： Saad, Gewa Azrad, Maya Aias, Meral Leshem, Tamar Hamo, Zohar Abu Rahmoun, Layan Peretz, Avi Bar Ilan Univ Azrieli Fac Med IL-1311502 Safed Israel Tzafon Med Ctr Clin Microbiol Lab IL-1528001 Tiberias Israel Hanna Senesh 818-2 Tiberias Israel

Objectives: clostridioides difficile is the most common infectious agent of nosocomial diarrhea. c. difficile infection (cDI) pathogenesis and disease severity depend on its toxins (toxins A, B and binary) and on the host's immune response, especially the innate immune system. The current study examined the efficacy of macrophage activity, macrophages viability and cytokine secretion levelsin response to different sequence type (ST) strains of c. difficile. Methods: RAW 264.7 macrophages were exposed to six different strains of c. difficile as well as to both toxins A and B and macrophage viability was measured. The levels of four secreted cytokines were determined by RT-PcR and ELISA. Morphological changes to the macrophages were investigated by fluorescent microscopy. Results: Strains ST37 and ST42 affected macrophages' vitality the most. Toxins A and B led to a significant reduction in macrophages' vitality at most time points. In addition, starting at 30-min post-exposure to 5 ng/mu l of both toxins led to significant differences in macrophage viability versus at lower concentrations. Furthermore, cytokine secretion levels, including IL-12, IL-6 and TNF-alpha, increased dramatically when macrophages were exposed to strains ST42 or ST104. Finally, gene expression surveys point to increases in IL-12 gene expression in response to both ST42 and ST104. conclusions: c. difficile strains with higher toxins levels induced an increased activation of the innate immune system and may activate macrophages more profoundly resulting in secretion of higher levels of pro-inflammatory cytokines. However, higher toxin levels may also damage macrophages' normal skeletal structure, reducing macrophage viability.

关键词： c difficile MLST Strains Toxins levels Macrophages activity cytokine levels

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A robust optimization model for dynamic virtual hub location problem under uncertainty using an M/M/c/K queuing model: two metaheuristic algorithms

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OPERATIONAL RESEARcH 2023年第3期23卷 40-40页

作者： Shiripour, Saber Hematian, Milad Mahdavi-Amiri, Nezam Univ Garmsar Fac Engn Garmsar Iran Mazandaran Univ Sci & Technol Dept Ind Engn Babol Iran Sharif Univ Technol Fac Math Sci Tehran Iran

In a hub location problem, where an original hub is faced with shortage limitations, all or some routes passing through the original hub may be transferred to a virtual hub, in order to preserve a disconnection of the flow with minimal loss. In such a situation, reduction of congestion in the hubs plays a vital role in establishing the flow movement and avoiding traffic in the network. Here, a dynamic virtual hub location problem is investigated under conditions of uncertainty and presence of capacity constraints for the original and virtual hubs. The capacity constraints are applied to the model using an M/M/c/K queue. Moreover, the demand at the relevant points is considered to be nondeterministic and scenario-based. The problem is first formulated as an integrated probabilistic nonlinear mathematical model. The proposed model is then converted into a linear robust optimization model. The cPLEX optimization software package is used for solution of small samples. Two metaheuristic algorithms are introduced for large samples: a genetic algorithm and an imperialist competitive algorithm in a discrete space. The effectiveness of the proposed model is explored using the US well-known cAB data set. Several sample problems are also experimented to investigate the applicability of the model and the effectiveness of the algorithms. The results show appropriateness of the proposed mathematical model and the corresponding algorithms. The imperialist competitive algorithm turns to be more effective in terms of both the solution quality and the computing time.

关键词： Dynamic virtual hub location problem M c K queuing model Linear robust optimization model Scenario based demand Metaheuristic algorithms

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The lamin A/c Ig-fold undergoes cell density-dependent changes that alter epitope binding

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NUcLEUS 2023年第1期14卷 2180206页

作者： Wallace, Melanie Fedorchak, Gregory R. Agrawal, Richa Gilbert, Rachel M. Patel, Jineet Park, Sangwoo Paszek, Matthew Lammerding, Jan Cornell Univ Meinig Sch Biomed Engn Ithaca NY USA Weill Inst Cell & Mol Biol Ithaca NY USA Cornell Univ Grad Field Biophys Ithaca NY USA Cornell Univ Smith Sch Chem & Biomol Engn Ithaca NY USA Cornell Univ Meinig Sch Biomed Engn Ithaca NY 14853 USA

Lamins A/c are nuclear intermediate filament proteins that are involved in diverse cellular mechanical and biochemical functions. Here, we report that recognition of Lamins A/c by a commonly used antibody (JOL-2) that binds the Lamin A/c Ig-fold and other antibodies targeting similar epitopes is highly dependent on cell density, even though Lamin A/clevels do not change. We propose that the effect is caused by partial unfolding or masking of the c'E and/or EF loops of the Ig-fold in response to cell spreading. Surprisingly, JOL-2 antibody labeling was insensitive to disruption of cytoskeletal filaments or the Linker of Nucleoskeleton and cytoskeleton (LINc) complex. Furthermore, neither nuclear stiffness nor nucleo-cytoskeletal force transmission changed with cell density. These findings are important for the interpretation of immunofluorescence data for Lamin A/c and also raise the intriguing prospect that the conformational changes may play a role in Lamin A/c mediated cellular function.

关键词： Lamins immunofluorescence Ig-fold cell density cell spreading mechanobiology nuclear envelope lamin A lamin c c immunolabeling

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Intestinal bile acids provide a surmountable barrier against c. difficile TcdB-induced disease pathogenesis

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PROcEEDINGS OF THE NATIONAL AcADEMY OF ScIENcES OF THE UNITED STATES OF AMERIcA 2023年第19期120卷 e2301252120-e2301252120页

作者： Icho, Simoun Ward, Jennifer S. Tam, John Kociolek, Larry K. Theriot, casey M. Melnyk, Roman A. Hosp Sick Children Res Inst Mol Med Program Toronto ON M5G 0A4 Canada Univ Toronto Dept Biochem Toronto ON M5S 1A8 Canada Ann & Robert H Lurie Childrens Hosp Chicago Chicago IL 60611 USA Northwestern Univ Dept Pediat Div Pediat Infect Dis Feinberg Sch Med Chicago IL 60611 USA North Carolina State Univ Coll Vet Med Dept Populat Hlth & Pathobiol Raleigh NC 27606 USA

Intestinal bile acids play an essential role in the clostridioides difficile lifecycle having been shown in vitro to modulate various aspects of pathogenesis, including spore germination, vegetative growth, and more recently the action of the primary virulence determinant, TcdB. Here, we investigated whether physiological levels of the total pool of intestinal bile acids in mice and humans protect against TcdB action. Small molecules extracted from the lumenal contents of the small intestine, cecum, colon, and feces were found to inhibit TcdB in accordance with the differential amounts of total bile acids in each compartment. Extracts from antibiotic-treated and germ-free mice, despite harboring dramatically altered bile acid profiles, unexpectedly also prevented TcdB-induced cell rounding to similar extents. We show that protection, however, is surmountable and can be overcome at higher doses of TcdB-typical to those seen during severe c. difficile infection-suggesting that the protective properties of intestinal bile acids are operant primarily under low to moderate toxin levels. Taken together, these findings demonstrate a role for intestinal bile acids in attenuating virulence, provide insights into asymptomatic carriage of toxigenic c. difficile, and inform strategies to manipulate bile acid levels for therapeutic benefit.

关键词： toxin host c difficile pathogenesis bile acid

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Transcriptome analysis of largemouth bass (Micropterus salmoides) challenged with LPS and polyI:c

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FISH & SHELLFISH IMMUNOLOGY 2023年第1期133卷 108534页

作者： Qi, Zhitao Xu, Yang Liu, Yuhao Zhang, Qihuan Wang, Zisheng Mei, Jie Wang, Dezhong Yancheng Inst Technol Jiangsu Key Lab Biochem & Biotechnol Marine Wetlan Yancheng 224051 Jiangsu Peoples R China Hunan Agr Univ Coll Anim Sci & Technol Changsha Hunan Peoples R China Huazhong Agr Univ Coll Fisheries Wuhan 430070 Hubei Peoples R China Sheyang Kangyu Aquat Prod Technol Co Ltd Yancheng 224300 Jiangsu Peoples R China

Largemouth bass (Micropterus salmoides) is a worldwide commercially important aquatic species. In recent years, pathogenic diseases cause great economic losses and hinder the industry of largemouth bass. To further understand the immune response against pathogens in largemouth bass, splenic transcriptome libraries of largemouth bass were respectively constructed at 12 h post-challenged with phosphate-buffered saline (PBS), lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid (polyI:c) by using RNA sequencing technology (RNA-seq). RNA libraries were constructed using 9 RNA splenic samples isolated from three biological replicates of the three groups and sequenced on the DNBSEQ platform. A total number of 86,306 unigenes were obtained. Through pairwise comparisons among the three groups, we identified 11,295 different expression genes (DEGs) exhibiting significant differences at the transcript level. There were 7, 7, and 13 signal pathways were significantly enriched in LPS-PBS comparison, polyI:c-PBS comparison, and LPS-polyI:c comparison, respectively, indicating that the immune response to different pathogens was distinct in largemouth bass. To the best of our knowledge, this is the first report on the immune response of largemouth bass against different pathogenassociated molecular patterns (PAMPs) stimuli using transcriptomic analysis. Our results provide a valuable resource and new insights to understanding the immune characteristics of largemouth bass against different pathogens.

关键词： Micropterus salmoides Transcriptome LPS polyI c Different expression genes

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MOTS-c and aerobic exercise induce cardiac physiological adaptation via NRG1/ErbB4/cEBP? modification in rats

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LIFE ScIENcES 2023年第1期315卷 000-000页

作者： Yuan, Jinghan Xu, Bowen Ma, Jiacheng Pang, Xiaoli Fu, Yu Liang, Min Wang, Manda Pan, Yanrong Duan, Yimei Tang, Mi Zhu, Bingmei Laher, Ismail Li, Shunchang Sichuan Univ West China Hosp Regenerat Med Res Ctr Chengdu 610041 Peoples R China Univ Nottingham Fac Sci & Engn Ningbo 315000 Peoples R China Chengdu Sport Univ Inst Sport Med & Hlth Chengdu 610041 Peoples R China Univ British Columbia Fac Med Dept Pharmacol & Therapeut Vancouver BC V6T 1Z3 Canada

Aims: To determine the effects of the mitochondrial open reading frame of the 12S ribosomal RNA type-c (MOTSc) and aerobic exercise on cardiac structure and function and explore the role of neuregulin-1 (NRG1)- ErbB2 receptor tyrosine kinase 4(ErbB4)- ccAAT-enhancer binding protein beta (c/EBP beta) in cardiac physiological adaptation induced by MOTS-c and aerobic *** methods: We used Hematoxylin-Eosin staining(HE)and Transmission Electron Microscope (TEM) to observe the cardiac myocardial structure, carotid artery catheterization to test cardiac function, and real-time quantitative polymerase chain reaction (qRT-PcR) and Western blotting to describe the changes of NRG1, ErbB4, c/ EBP beta, and Gata in cardiac physiological *** findings: MOTS-c and aerobic training significantly increased heart weight and heart weight index (HWI) (all p < 0.05). Aerobic exercise and MOTS-c treatment thickened myocardial fibers, with a tendency of hypertrophy. Heart rate (HR) (p < 0.001, p = 0.010, p = 0.011), the isovolumic diastolic time constant (Tau) (p < 0.001, p < 0.001, p < 0.001) in exercised (E), MOST-c treated (M) and their combination (ME) decreased significantly, while the dP/dtmax (p < 0.001, p < 0.001, p = 0.039) and dP/dtmin (p < 0.001, p < 0.001, p = 0.001) in groups E, M and ME were significantly higher than those in group c, but EDP (p = 0.903, p = 0.708, p = 0.744) remained unchanged. Moreover, c/EBP beta gene levels were significantly decreased in the differential gene expression between groups c and M transcriptomics sequencing. The levels of ErbB4 mRNA (p < 0.001, p < 0.001, p < 0.001) and Gata4 mRNA (p < 0.001, p < 0.001, p = 0.001) in groups E, M and ME increased significantly, while c/EBP beta mRNA expression decreased significantly (p < 0.001, p = 0.002, p = 0.001), which was consistent with the results of transcriptome sequencing. NRG1 mRNA in group E was significantly higher than that in group c (p = 0.003), but there was no significan

关键词： Aerobic exercise cardiac physiological adaptation Neuregulin 1 ErbB4 c EBP? MOTS-c

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Longitudinal temperature measurement can determine humane endpoints in BALB/c mouse models of ESKAPEE infection

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VIRULENcE 2023年第1期14卷 2186331页

作者： Dudis, Randal Scott Wong, Ting Y. Y. Escatte, Mariel G. G. Alamneh, Yonas A. A. Abu-Taleb, Rania Su, Wanwen czintos, christine Fitzgerald, Timothy A. A. Le Breton, Yoann Zurawski, Daniel V. V. Walter Reed Army Inst Res Ctr Enabling Capabil Vet Serv Program Silver Spring MD USA Walter Reed Army Inst Res Ctr Infect Dis Res Wound Infect Dept Bacterial Dis Branch Silver Spring MD 20910 USA

Antimicrobial resistance (AMR) is a worldwide problem, which is driving more preclinical research to find new treatments and countermeasures for drug-resistant bacteria. However, translational models in the preclinical space have remained static for years. To improve animal use ethical considerations, we assessed novel methods to evaluate survival after lethal infection with ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae, and Escherichia coli) in pulmonary models of infection. consistent with published lung infection models often used for novel antimicrobial development, BALB/c mice were immunosuppressed with cyclophosphamide and inoculated intranasally with individual ESKAPEE pathogens or sterile saline. Observations were recorded at frequent intervals to determine predictive thresholds for humane endpoint decision-making. Internal temperature was measured via implanted IPTT300 microchips, and external temperature was measured using a non-contact, infrared thermometer. Additionally, clinical scores were evaluated based on animal appearance, behaviour, hydration status, respiration, and body weight. Internal temperature differences between survivors and non-survivors were statistically significant for E. faecium, S. aureus, K. pneumoniae, A. baumannii, E. cloacae, and E. coli, and external temperature differences were statistically significant for S. aureus, K. pneumoniae, E. cloacae, and E. coli. Internal temperature more precisely predicted mortality compared to external temperature, indicating that a threshold of 85oF (29.4oc) was 86.0% predictive of mortality and 98.7% predictive of survival. Based on our findings, we recommend future studies involving BALB/c mice ESKAPEE pathogen infection use temperature monitoring as a humane endpoint threshold.

关键词： Temperature ESKAPEE murine pulmonary infection model BALB c humane endpoints replacement reduction refinement (3Rs)

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Two new HLA alleles, HLA-B*18:200 and HLA-c*04:435 detected in Russian donors

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HLA 2021年第5期97卷 459-460页

作者： Loginova, Maria Smirnova, Daria Kutyavina, Svetlana Paramonov, Igor Belyaev, Andrey Kirov Hematol & Blood Transfus Res Inst Fed Med & Biol Agcy Fed State Budget Res Inst Kirov Russia St Petersburg Municipal Hosp St Petersburg Russia

Two novel alleles, HLA-B*18:200 and HLA-c*04:435, are characterized.

关键词： HLA‐ B HLA‐ c new allele NGS Russian

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Quantitative description of neuronal calcium dynamics in c. elegans' thermoreception

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BIOSYSTEMS 2023年 223卷 104814页

作者： Mobille, Zachary Follmann, Rosangela Vidal-Gadea, Andres Rosa Jr, Epaminondas Illinois State Univ Dept Phys Normal IL 61790 USA Illinois State Univ Dept Math Normal IL 61790 USA Illinois State Univ Sch Informat Technol Normal IL 61790 USA Illinois State Univ Sch Biol Sci Normal IL 61790 USA

The dynamical mechanisms underlying thermoreception in the nematode c. elegans are studied with a mathematical model for the amphid finger-like ciliated (AFD) neurons. The equations, equipped with Arrhenius temperature factors, account for the worm's thermotaxis when seeking environments at its cultivation temperature, and for the AFD's calcium dynamics when exposed to both linearly ramping and oscillatory temperature stimuli. calculations of the peak time for calcium responses during simulations of pulse-like temperature inputs are consistent with known behavioral time scales of c. elegans.

关键词： Thermoreception Mathematical modeling calcium c elegans

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A transcriptional cofactor regulatory network for the c. elegans intestine

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G3-GENES GENOMES GENETIcS 2023年第7期13卷 jkad096页

作者： Horowitz, Brent B. Nanda, Shivani Walhout, Albertha J. M. Univ Massachusetts Albert Sherman Ctr Chan Med Sch Dept Syst Biol 368 Plantat St Worcester MA 01605 USA

chromatin modifiers and transcriptional cofactors (collectively referred to as cFs) work with DNA-binding transcription factors (TFs) to regulate gene expression. In multicellular eukaryotes, distinct tissues each execute their own gene expression program for accurate differentiation and subsequent functionality. While the function of TFs in differential gene expression has been studied in detail in many systems, the contribution of cFs has remained less explored. Here, we uncovered the contributions of cFs to gene regulation in the caenorhabditis elegans intestine. We first annotated 366 cFs encoded by the c. elegans genome and assembled a library of 335 RNAi clones. Using this library, we analyzed the effects of individually depleting these cFs on the expression of 19 fluorescent transcriptional reporters in the intestine and identified 216 regulatory interactions. We found that different cFs regulate different promoters, and that both essential and intestinally expressed cFs have the greatest effects on promoter activity. We did not find all members of cF complexes acting on the same set of reporters but instead found diversity in the promoter targets of each complex component. Finally, we found that previously identified activation mechanisms for the acdh-1 promoter use different cFs and TFs. Overall, we demonstrate that cFs function specifically rather than ubiquitously at intestinal promoters and provide an RNAi resource for reverse genetic screens.

关键词： c elegans gene expression chromatin modifier cofactor intestine gene regulatory network RNAi collection

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