233 research outputs found
Inferring the Sign of Kinase-Substrate Interactions by Combining Quantitative Phosphoproteomics with a Literature-Based Mammalian Kinome Network
Protein phosphorylation is a reversible post-translational modification
commonly used by cell signaling networks to transmit information about the
extracellular environment into intracellular organelles for the regulation of
the activity and sorting of proteins within the cell. For this study we
reconstructed a literature-based mammalian kinase-substrate network from
several online resources. The interactions within this directed graph network
connect kinases to their substrates, through specific phosphosites including
kinase-kinase regulatory interactions. However, the "signs" of links,
activation or inhibition of the substrate upon phosphorylation, within this
network are mostly unknown. Here we show how we can infer the "signs"
indirectly using data from quantitative phosphoproteomics experiments applied
to mammalian cells combined with the literature-based kinase-substrate network.
Our inference method was able to predict the sign for 321 links and 153
phosphosites on 120 kinases, resulting in signed and directed subnetwork of
mammalian kinase-kinase interactions. Such an approach can rapidly advance the
reconstruction of cell signaling pathways and networks regulating mammalian
cells.Comment: 5 page, 3 figures, IEEE-BIBE confrenc
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Confounding effects in gene expression and their impact on downstream analysis
The reconstruction of gene regulatory networks is one of the milestones of computational system biology. We introduce a new implementation of ARACNe (Algorithm for the Reconstruction of Accurate Cellular Networks) to reverse engineer transcriptional regulatory networks with improved mutual information estimators and significant improvement in performance. In the context of data driven network inference we identify two major confounding biases and introduce solutions to remove some of the discussed biases. First we identify prevalent spatial biases in gene expression studies derived from plate based designs. We investigate the gene expression profiles of a million samples from the LINCS dataset and find that the vast majority (96%) of the tested plates is affected by significant spatial bias. We can show that our proposed method to correct these biases results in a significant improvement of similarity between biological replicates assayed in different plates. Lastly we discuss the effect of CNV on gene expression and its confounding effect on the correlation landscape of genes in the context of cancer samples. We propose a method that removes the variance in gene expression explained by CNV and show that TF target predictions can be significantly improved
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A versatile and customizable low-cost 3D-printed open standard for microscopic imaging
Modern microscopes used for biological imaging often present themselves as black boxes whose precise operating principle remains unknown, and whose optical resolution and price seem to be in inverse proportion to each other. With UC2 (You. See. Too.) we present a low-cost, 3D-printed, open-source, modular microscopy toolbox and demonstrate its versatility by realizing a complete microscope development cycle from concept to experimental phase. The self-contained incubator-enclosed brightfield microscope monitors monocyte to macrophage cell differentiation for seven days at cellular resolution level (e.g. 2 μm). Furthermore, by including very few additional components, the geometry is transferred into a 400 Euro light sheet fluorescence microscope for volumetric observations of a transgenic Zebrafish expressing green fluorescent protein (GFP). With this, we aim to establish an open standard in optics to facilitate interfacing with various complementary platforms. By making the content and comprehensive documentation publicly available, the systems presented here lend themselves to easy and straightforward replications, modifications, and extensions
Double Blind, Randomised Controlled Trial
Purpose Surgical patients are at high risk for developing infectious
complications and postoperative delirium. Prolonged infections and delirium
result in worse outcome. Granulocyte-macrophage colony-stimulating factor (GM-
CSF) and influenza vaccination are known to increase HLA-DR on monocytes and
improve immune reactivity. This study aimed to investigate whether GM-CSF or
vaccination reverses monocyte deactivation. Secondary aims were whether it
decreases infection and delirium days after esophageal or pancreatic resection
over time. Methods In this prospective, randomized, placebo-controlled,
double-blind, double dummy trial setting on an interdisciplinary ICU of a
university hospital 61 patients with immunosuppression (monocytic HLA-DR
[mHLA-DR] <10,000 monoclonal antibodies [mAb] per cell) on the first day after
esophageal or pancreatic resection were treated with either GM-CSF (250
μg/m2/d), influenza vaccination (Mutagrip 0.5 ml/d) or placebo for a maximum
of 3 consecutive days if mHLA-DR remained below 10,000 mAb per cell. HLA-DR on
monocytes was measured daily until day 5 after surgery. Infections and
delirium were followed up for 9 days after surgery. Primary outcome was HLA-DR
on monocytes, and secondary outcomes were duration of infection and delirium.
Results mHLA-DR was significantly increased compared to placebo (p < 0.001)
and influenza vaccination (p < 0.001) on the second postoperative day.
Compared with placebo, GM-CSF-treated patients revealed shorter duration of
infection (p < 0.001); the duration of delirium was increased after
vaccination (p = 0.003). Conclusion Treatment with GM-CSF in patients with
postoperative immune suppression was safe and effective in restoring monocytic
immune competence. Furthermore, therapy with GM-CSF reduced duration of
infection in immune compromised patients. However, influenza vaccination
increased duration of delirium after major surgery
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Systems Analysis Implicates WAVE2 Complex in the Pathogenesis of Developmental Left-Sided Obstructive Heart Defects.
Genetic variants are the primary driver of congenital heart disease (CHD) pathogenesis. However, our ability to identify causative variants is limited. To identify causal CHD genes that are associated with specific molecular functions, the study used prior knowledge to filter de novo variants from 2,881 probands with sporadic severe CHD. This approach enabled the authors to identify an association between left ventricular outflow tract obstruction lesions and genes associated with the WAVE2 complex and regulation of small GTPase-mediated signal transduction. Using CRISPR zebrafish knockdowns, the study confirmed that WAVE2 complex proteins brk1, nckap1, and wasf2 and the regulators of small GTPase signaling cul3a and racgap1 are critical to cardiac development
a randomized controlled study
Background Uncertainty persists regarding the optimal ventilatory strategy in
trauma patients developing acute respiratory distress syndrome (ARDS). This
work aims to assess the effects of two mechanical ventilation strategies with
high positive end-expiratory pressure (PEEP) in experimental ARDS following
blunt chest trauma. Methods Twenty-six juvenile pigs were anesthetized,
tracheotomized and mechanically ventilated. A contusion was applied to the
right chest using a bolt-shot device. Ninety minutes after contusion, animals
were randomized to two different ventilation modes, applied for 24 h: Twelve
pigs received conventional pressure-controlled ventilation with moderately low
tidal volumes (VT, 8 ml/kg) and empirically chosen high external PEEP
(16cmH2O) and are referred to as the HP-CMV-group. The other group (n = 14)
underwent high-frequency inverse-ratio pressure-controlled ventilation (HFPPV)
involving respiratory rate of 65breaths · min−1, inspiratory-to-expiratory-
ratio 2:1, development of intrinsic PEEP and recruitment maneuvers, compatible
with the rationale of the Open Lung Concept. Hemodynamics, gas exchange and
respiratory mechanics were monitored during 24 h. Computed tomography and
histology were analyzed in subgroups. Results Comparing changes which occurred
from randomization (90 min after chest trauma) over the 24-h treatment period,
groups differed statistically significantly (all P values for group effect
<0.001, General Linear Model analysis) for the following parameters (values
are mean ± SD for randomization vs. 24-h): PaO2 (100 % O2) (HFPPV 186 ± 82 vs.
450 ± 59 mmHg; HP-CMV 249 ± 73 vs. 243 ± 81 mmHg), venous admixture (HFPPV 34
± 9.8 vs. 11.2 ± 3.7 %; HP-CMV 33.9 ± 10.5 vs. 21.8 ± 7.2 %), PaCO2 (HFPPV
46.9 ± 6.8 vs. 33.1 ± 2.4 mmHg; HP-CMV 46.3 ± 11.9 vs. 59.7 ± 18.3 mmHg) and
normally aerated lung mass (HFPPV 42.8 ± 11.8 vs. 74.6 ± 10.0 %; HP-CMV 40.7 ±
8.6 vs. 53.4 ± 11.6 %). Improvements occurring after recruitment in the HFPPV-
group persisted throughout the study. Peak airway pressure and VT did not
differ significantly. HFPPV animals had lower atelectasis and inflammation
scores in gravity-dependent lung areas. Conclusions In this model of ARDS
following unilateral blunt chest trauma, HFPPV ventilation improved
respiratory function and fulfilled relevant ventilation endpoints for trauma
patients, i.e. restoration of oxygenation and lung aeration while avoiding
hypercapnia and respiratory acidosis
Integration of protein phosphorylation, acetylation, and methylation data sets to outline lung cancer signaling networks
Integrated multiomics network analysis reveals signaling profiles in lung cancer.</jats:p
Oxygenation inhibits the physiological tissue-protecting mechanism and thereby exacerbates acute inflammatory lung injury
Acute respiratory distress syndrome (ARDS) usually requires symptomatic supportive therapy by intubation and mechanical ventilation with the supplemental use of high oxygen concentrations. Although oxygen therapy represents a life-saving measure, the recent discovery of a critical tissue-protecting mechanism predicts that administration of oxygen to ARDS patients with uncontrolled pulmonary inflammation also may have dangerous side effects. Oxygenation may weaken the local tissue hypoxia-driven and adenosine A2A receptor (A2AR)-mediated anti-inflammatory mechanism and thereby further exacerbate lung injury. Here we report experiments with wild-type and adenosine A2AR-deficient mice that confirm the predicted effects of oxygen. These results also suggest the possibility of iatrogenic exacerbation of acute lung injury upon oxygen administration due to the oxygenation-associated elimination of A2AR-mediated lung tissue-protecting pathway. We show that this potential complication of clinically widely used oxygenation procedures could be completely prevented by intratracheal injection of a selective A2AR agonist to compensate for the oxygenation-related loss of the lung tissue-protecting endogenous adenosine. The identification of a major iatrogenic complication of oxygen therapy in conditions of acute lung inflammation attracts attention to the need for clinical and epidemiological studies of ARDS patients who require oxygen therapy. It is proposed that oxygen therapy in patients with ARDS and other causes of lung inflammation should be combined with anti-inflammatory measures, e.g., with inhalative application of A2AR agonists. The reported observations may also answer the long-standing question as to why the lungs are the most susceptible to inflammatory injury and why lung failure usually precedes multiple organ failure
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