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https://www.readbyqxmd.com/read/28538158/glnk-facilitates-the-dynamic-regulation-of-bacterial-nitrogen-assimilation
#1
Adam Gosztolai, Jörg Schumacher, Volker Behrends, Jacob G Bundy, Franziska Heydenreich, Mark H Bennett, Martin Buck, Mauricio Barahona
Ammonium assimilation in Escherichia coli is regulated by two paralogous proteins (GlnB and GlnK), which orchestrate interactions with regulators of gene expression, transport proteins, and metabolic pathways. Yet how they conjointly modulate the activity of glutamine synthetase, the key enzyme for nitrogen assimilation, is poorly understood. We combine experiments and theory to study the dynamic roles of GlnB and GlnK during nitrogen starvation and upshift. We measure time-resolved in vivo concentrations of metabolites, total and posttranslationally modified proteins, and develop a concise biochemical model of GlnB and GlnK that incorporates competition for active and allosteric sites, as well as functional sequestration of GlnK...
May 23, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28518103/structure-function-studies-in-mouse-embryonic-stem-cells-using-recombinase-mediated-cassette-exchange
#2
Tim Pieters, Lieven Haenebalcke, Kenneth Bruneel, Niels Vandamme, Tino Hochepied, Jolanda van Hengel, Dagmar Wirth, Geert Berx, Jody J Haigh, Frans van Roy, Steven Goossens
Gene engineering in mouse embryos or embryonic stem cells (mESCs) allows for the study of the function of a given protein. Proteins are the workhorses of the cell and often consist of multiple functional domains, which can be influenced by posttranslational modifications. The depletion of the entire protein in conditional or constitutive knock-out (KO) mice does not take into account this functional diversity and regulation. An mESC line and a derived mouse model, in which a docking site for FLPe recombination-mediated cassette exchange (RMCE) was inserted within the ROSA26 (R26) locus, was previously reported...
April 27, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28497532/arabidopsis-thaliana-epoxide-hydrolase1-ateh1-is-a-cytosolic-epoxide-hydrolase-involved-in-the-synthesis-of-poly-hydroxylated-cutin-monomers
#3
Emmanuelle Pineau, Lin Xu, Hugues Renault, Adrien Trolet, Nicolas Navrot, Pascaline Ullmann, Bertrand Légeret, Gaëtan Verdier, Fred Beisson, Franck Pinot
Epoxide hydrolases (EHs) are present in all living organisms. They have been extensively characterized in mammals; however, their biological functions in plants have not been demonstrated. Based on in silico analysis, we identified AtEH1 (At3g05600), a putative Arabidopsis thaliana epoxide hydrolase possibly involved in cutin monomer synthesis. We expressed AtEH1 in yeast and studied its localization in vivo. We also analyzed the composition of cutin from A. thaliana lines in which this gene was knocked out...
May 12, 2017: New Phytologist
https://www.readbyqxmd.com/read/28497232/tamoxifen-for-induction-of-cre-recombination-may-confound-fibrosis-studies-in-female-mice
#4
Lucas L Falke, Roel Broekhuizen, Alwin Huitema, Erik Maarseveen, Tri Q Nguyen, Roel Goldschmeding
A variety of conditional knock-out mice relying on Tamoxifen-driven ERT2/Cre -mediated recombination are available and have been used to study involvement of specific genes in kidney disease. However, recent data suggest that Tamoxifen itself might attenuate fibrosis when administered during experimental models of kidney disease. It has remained unclear whether this still applies also if kidney damage is initiated after a wash-out period has been implemented. Here we report that the commonly applied regimen of administration of 4 alternate day doses of 1mg Tamoxifen per mouse until 14 days prior to start of the actual experiment, in this case the induction of obstructive nephropathy by Unilateral Ureteral Obstruction (UUO), still attenuated fibrosis in female obstructed mouse kidneys, whereas this effect was not seen in male obstructed kidneys...
May 11, 2017: Journal of Cell Communication and Signaling
https://www.readbyqxmd.com/read/28488216/knock-out-serum-replacement-and-melatonin-effects-on-germ-cell-differentiation-in-murine-testicular-explant-cultures
#5
Ahmed Reda, Halima Albalushi, Sheyla Cisneros Montalvo, Mirja Nurmio, Zeliha Sahin, Mi Hou, Niels Geijsen, Jorma Toppari, Olle Söder, Jan-Bernd Stukenborg
Finding robust culture conditions for in vitro maturation (IVM) of male germ cells is still a challenge. Recently, a testis organ culture method, using Knockout Serum Replacement (KSR), was suggested as a promising approach. However, the efficiency of that model is still not optimal. Hence, we have tried to establish the culture conditions in two laboratories, and to improve the reliability of the culture system to generate mature germ cells. Male mice at three days of age were sacrificed. Testes were cut into small pieces which were cultured atop agarose stands, using Minimum Essential Medium alpha supplemented with different supplements; melatonin, Glutamax, and different concentrations of KSR...
May 9, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28481957/deletion-of-shp2-in-bronchial-epithelial-cells-impairs-il-25-production-in-vitro-but-has-minor-influence-on-asthmatic-inflammation-in-vivo
#6
Zhangwei Qiu, Jiesen Zhou, Fang Liu, Xuejun Qin, Yuanrong Dai, Yuehai Ke, Zhihua Chen, Wen Li, Songmin Ying, Huahao Shen
Shp2 played an important role in cigarette-smoke-mediated inflammation, surfactant homeostasis and asthmatic airway remodeling. However, whether shp2 plays a key role in epithelium-associated allergic reaction is still unknown. In this study, LPS and OVA were observed to induce the production of IL-25 in bronchial epithelial cells in vitro via the activation of MAPK p38 and JNK. Furthermore, blockage of Shp2 by its specific inhibitor PHPS1 or by siRNA-mediated depletion was found to reduce the production of IL-25 in epithelial cells as well as the up-regulated LPS-triggered activation of JNK but not p38...
2017: PloS One
https://www.readbyqxmd.com/read/28437187/synergy-between-choroid-plexus-epithelial-cell-conditioned-medium-and-knockout-serum-replacement-converts-human-adipose-derived-stem-cells-to-dopamine-secreting-neurons
#7
Mahdi Eskandarian Boroujeni, Mossa Gardaneh, Mehrnoosh Hasan Shahriari, Abbas Aliaghaei, Sanaz Hasani
Human adipose-derived stem cells (hADSCs) have great capacity to differentiate into mesodermal origins as well as nonmesodermal lineages, including neural cells. This valuable feature paves the way for the therapeutic application of hADSCs for neurodegenerative maladies such as Parkinson's disease (PD). We tested the capacity of choroid plexus epithelial cell-conditioned medium (CPEC-CM) alone or cocktailed with knockout serum (KS) to induce dopaminergic (DAergic) differentiation of hADSCs. To this end, hADSCs from lipoaspirate were phenotypically characterized and shown to maintain mesodermal multipotency so that selected media easily differentiated them into osteoblasts, chondrocytes, and adipocytes...
April 27, 2017: Rejuvenation Research
https://www.readbyqxmd.com/read/28432097/diazotrophy-overcomes-the-deleterious-growth-phenotype-of-glne-deletion-in-azotobacter-vinelandii
#8
Florence Mus, Alex Tseng, Ray Dixon, John W Peters
Overcoming the inhibitory effects of excess environmental ammonium on nitrogenase synthesis or activity, or preventing ammonium assimilation, have both been considered as strategies to increase the amount of fixed nitrogen transferred from bacterial to plant partners in associative or symbiotic plant-diazotroph relationships. The GlnE adenylyltransferase/adenylyl-removing enzyme catalyzes reversible adenylylation of glutamine synthetase (GS), thereby affecting the post translational regulation of ammonium assimilation critical for appropriate coordination of carbon and nitrogen assimilation...
April 21, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28429761/a-specific-nanobody-prevents-amyloidogenesis-of-d76n-%C3%AE-2-microglobulin-in-vitro-and-modifies-its-tissue-distribution-in-vivo
#9
Sara Raimondi, Riccardo Porcari, P Patrizia Mangione, Guglielmo Verona, Julien Marcoux, Sofia Giorgetti, Graham W Taylor, Stephan Ellmerich, Maurizio Ballico, Stefano Zanini, Els Pardon, Raya Al-Shawi, J Paul Simons, Alessandra Corazza, Federico Fogolari, Manuela Leri, Massimo Stefani, Monica Bucciantini, Julian D Gillmore, Philip N Hawkins, Maurizia Valli, Monica Stoppini, Carol V Robinson, Jan Steyaert, Gennaro Esposito, Vittorio Bellotti
Systemic amyloidosis is caused by misfolding and aggregation of globular proteins in vivo for which effective treatments are urgently needed. Inhibition of protein self-aggregation represents an attractive therapeutic strategy. Studies on the amyloidogenic variant of β2-microglobulin, D76N, causing hereditary systemic amyloidosis, have become particularly relevant since fibrils are formed in vitro in physiologically relevant conditions. Here we compare the potency of two previously described inhibitors of wild type β2-microglobulin fibrillogenesis, doxycycline and single domain antibodies (nanobodies)...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28417080/applying-a-systems-approach-to-thyroid-physiology-looking-at-the-whole-with-a-mitochondrial-perspective-instead-of-judging-single-tsh-values-or-why-we-should-know-more-about-mitochondria-to-understand-metabolism
#10
REVIEW
Roy Moncayo, Helga Moncayo
Classical thinking in endocrine physiology squeezes our diagnostic handling into a simple negative feedback mechanism with a controller and a controlled variable. In the case of the thyroid this is reduced to TSH and fT3 and fT4, respectively. The setting of this tight notion has no free space for any additions. In this paper we want to challenge this model of limited application by proposing a construct based on a systems approach departing from two basic considerations. In first place since the majority of cases of thyroid disease develop and appear during life it has to be considered as an acquired condition...
June 2017: BBA Clinical
https://www.readbyqxmd.com/read/28410129/epigenetics-of-reproductive-infertility
#11
Laxmidhar Das, Sabnam Parbin, Nibedita Pradhan, Chahat Kausar, Samir K Patra
Infertility is a complex pathophysiological condition. It may caused by specific or multiple physical and physiological factors, including abnormalities in homeostasis, hormonal imbalances and genetic alterations. In recent times various studies implicated that, aberrant epigenetic mechanisms are associated with reproductive infertility. There might be transgenerational effects associated with epigenetic modifications of gametes and studies suggest the importance of alterations in epigenetic modification at early and late stages of gametogenesis...
June 1, 2017: Frontiers in Bioscience (Scholar Edition)
https://www.readbyqxmd.com/read/28409342/zebrafish-as-a-model-of-kidney-disease
#12
Elvin E Morales, Rebecca A Wingert
Animal models have been an invaluable means to advance biomedical research as they provide experimental avenues for cellular and molecular investigations of disease pathology. The zebrafish (Danio rerio) is a good alternative to mammalian models that can be used to apply powerful genetic experimental methods normally used in invertebrates to answer questions about vertebrate development and disease. In the case of the kidney, the zebrafish has proven itself to be an applicable and versatile experimental system, mainly due to the simplicity of its pronephros, which contains two nephrons that possess conserved structural and physiological aspects with mammalian nephrons...
2017: Results and Problems in Cell Differentiation
https://www.readbyqxmd.com/read/28401532/gram-positive-pneumonia-augments-non-small-cell-lung-cancer-metastasis-via-host-toll-like-receptor-2-activation
#13
Stephen D Gowing, Simon C Chow, Jonathan J Cools-Lartigue, Crystal B Chen, Sara Najmeh, Henry Y Jiang, France Bourdeau, Annie Beauchamp, Ugo Mancini, Isabelle Angers, Betty Giannias, Jonathan D Spicer, Simon Rousseau, Salman T Qureshi, Lorenzo E Ferri
Surgical resection of early stage non-small cell lung cancer (NSCLC) is necessary for cure. However, rates of post-operative bacterial pneumonias remain high and may confer an increased risk for metastasis. Toll-like receptors (TLRs) mediate the inflammatory cascade by recognizing microbial products at the surface of numerous cell types in the lung; however, little is known about how host TLRs influence NSCLC metastasis. TLR2 recognizes gram-positive bacterial cell wall components activating innate immunity...
April 12, 2017: International Journal of Cancer. Journal International du Cancer
https://www.readbyqxmd.com/read/28397054/effects-of-rna-interference-combined-with-ultrasonic-irradiation-and-sonovue-microbubbles-on-expression-of-stat3-gene-in-keratinocytes-of-psoriatic-lesions
#14
Li-Wei Ran, Hao Wang, Dong Lan, Hong-Xia Jia, Si-Si Yu
The most effective sequence of small interfering RNA (siRNA) silencing STAT3 of psoriatic keratinocytes (KCs) was screened out, and the effects of the most effective siRNA combined with ultrasonic irradiation and SonoVue microbubbles on the expression of STAT3 of KCs and the dose- and time-response were investigated. Three chemically-synthetic siRNAs targeting STAT3 carried by Lipofectamine 3000 were transfected into KCs, and the effects on STAT3 expression were detected, then the most effective siRNA was selected for the subsequent experiments...
April 2017: Journal of Huazhong University of Science and Technology. Medical Sciences
https://www.readbyqxmd.com/read/28392759/calcium-dependent-and-synapsin-dependent-pathways-for-the-presynaptic-actions-of-bdnf
#15
Qing Cheng, Sang-Ho Song, George J Augustine
We used cultured hippocampal neurons to determine the signaling pathways mediating brain-derived neurotrophic factor (BDNF) regulation of spontaneous glutamate and GABA release. BDNF treatment elevated calcium concentration in presynaptic terminals; this calcium signal reached a peak within 1 min and declined in the sustained presence of BDNF. This BDNF-induced transient rise in presynaptic calcium was reduced by SKF96365, indicating that BDNF causes presynaptic calcium influx via TRPC channels. BDNF treatment increased the frequency of miniature excitatory postsynaptic currents (mEPSCs)...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/28390857/targeted-deletion-of-the-hoxa-cluster-affects-b-lymphopoiesis-through-depletion-of-early-lymphoid-progenitors
#16
Charles-Étienne Lebert-Ghali, Alexander Thompson, Heather J Melichar, Janet J Bijl
It is well established that Hoxa genes play a critical role in the proliferative capacity of adult hematopoietic stem and progenitor cells, but the importance of Hoxa genes in later stages of hematopoietic differentiation is less clear. Previously, we observed that B-cell numbers were reduced in adult mice in which Hoxa deletion was induced. In the current study, we investigated the requirement of Hoxa genes at different stages of B-cell development. Using an MxCre-inducible conditional knock-out mouse model, we showed that immature B-cell fractions and early lymphoid progenitors were markedly reduced in the absence of Hoxa, whereas mature B-cell populations were found at levels comparable to controls...
April 5, 2017: Experimental Hematology
https://www.readbyqxmd.com/read/28387990/cdh13-and-adipoq-gene-knockout-alter-instrumental-and-pavlovian-drug-conditioning
#17
C P King, L Militello, A Hart, C L St Pierre, E Leung, C L Versaggi, N Roberson, J Catlin, A A Palmer, J B Richards, P J Meyer
Genome-wide association studies in humans have suggested that variants of the cadherin-13 (CDH13) gene are associated with substance use disorder, subjective response to amphetamine, and attention deficit hyperactivity disorder. To examine the role of the Cdh13 and its peptide ligand adiponectin (AdipoQ) in addiction-related behaviors, we assessed Cdh13 knockout (KO) rats and AdipoQ KO mice using intravenous cocaine self-administration and conditioned place preference (CPP) paradigms. During intravenous cocaine self-administration, male Cdh13 heterozygous (+/-) and KO (-/-) rats showed increased cue-induced reinstatement compared with wild-type (WT) rats when presented with a cocaine-paired stimulus, whereas female Cdh13 rats showed no differences across genotype...
April 7, 2017: Genes, Brain, and Behavior
https://www.readbyqxmd.com/read/28382046/evidence-for-gaba-induced-systemic-gaba-accumulation-in-arabidopsis-upon-wounding
#18
Sandra S Scholz, Jaiana Malabarba, Michael Reichelt, Monika Heyer, Frank Ludewig, Axel Mithöfer
The non-proteinogenic amino acid γ-aminobutyric acid (GABA) is present in all plant species analyzed so far. Its synthesis is stimulated by either acidic conditions occurring after tissue disruption or higher cytosolic calcium level. In mammals, GABA acts as inhibitory neurotransmitter but its function in plants is still not well understood. Besides its involvement in abiotic stress resistance, GABA has a role in the jasmonate-independent defense against invertebrate pests. While the biochemical basis for GABA accumulation in wounded leaves is obvious, the underlying mechanisms for wounding-induced GABA accumulation in systemic leaves remained unclear...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28379360/core-genes-evolve-rapidly-in-the-long-term-evolution-experiment-with-escherichia-coli
#19
Rohan Maddamsetti, Philip J Hatcher, Anna G Green, Barry L Williams, Debora S Marks, Richard E Lenski
Bacteria can evolve rapidly under positive selection owing to their vast numbers, allowing their genes to diversify by adapting to different environments. We asked whether the same genes that evolve rapidly in the long-term evolution experiment with Escherichia coli (LTEE) have also diversified extensively in nature. To make this comparison, we identified ∼2000 core genes shared among 60 E. coli strains. During the LTEE, core genes accumulated significantly more nonsynonymous mutations than flexible (i.e...
April 4, 2017: Genome Biology and Evolution
https://www.readbyqxmd.com/read/28376796/ahcoda-db-a-data-repository-with-web-based-mining-tools-for-the-analysis-of-automated-high-content-mouse-phenomics-data
#20
Bastijn Koopmans, August B Smit, Matthijs Verhage, Maarten Loos
BACKGROUND: Systematic, standardized and in-depth phenotyping and data analyses of rodent behaviour empowers gene-function studies, drug testing and therapy design. However, no data repositories are currently available for standardized quality control, data analysis and mining at the resolution of individual mice. DESCRIPTION: Here, we present AHCODA-DB, a public data repository with standardized quality control and exclusion criteria aimed to enhance robustness of data, enabled with web-based mining tools for the analysis of individually and group-wise collected mouse phenotypic data...
April 4, 2017: BMC Bioinformatics
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