Reporter mice for isolating and auditing cell type‐specific extracellular vesicles in vivo

Extracellular vesicles (EVs) are abundant, lipid‐enclosed vectors that contain nucleic acids and proteins, they can be secreted from donor cells and freely circulate, and they can be engulfed by recipient cells thus enabling systemic communication between heterotypic cell types. However, genetic tools for labeling, isolating, and auditing cell type‐specific EVs in vivo, without prior in vitro manipulation, are lacking. We have used CRISPR‐Cas9‐mediated genome editing to generate mice bearing a CD63‐emGFP^{loxP/stop/loxP} knock‐in cassette that enables the specific labeling of circulating CD63⁺ vesicles from any cell type when crossed with lineage‐specific Cre recombinase driver mice. As proof‐of‐principle, we have crossed these mice with Cdh5‐Cre^ERT2 mice to generate CD63^emGFP+ vasculature. Using these mice, we show that developing vasculature is marked with emerald GFP (emGFP) following tamoxifen administration to pregnant females. In adult mice, quiescent vasculature and angiogenic vasculature (in tumors) is also marked with emGFP. Moreover, whole plasma‐purified EVs contain a subpopulation of emGFP⁺ vesicles that are derived from the endothelium, co‐express additional EV (e.g., CD9 and CD81) and endothelial cell (e.g., CD105) markers, and they harbor specific miRNAs (e.g., miR‐126, miR‐30c, and miR‐125b). This new mouse strain should be a useful genetic tool for generating cell type‐specific, CD63⁺ EVs that freely circulate in serum and can subsequently be isolated and characterized using standard methodologies.     

Environmental sustainability of orthopedic devices produced with powder bed fusion

Additive manufacturing consists in melting metallic powders to produce objects from 3D data, layer upon layer. Its industrial applications range from automotive, biomedical (e.g., prosthetic implants for dentistry and orthopedics), aeronautics and others. This study uses life cycle assessment to evaluate the possible improvement in environmental performance of laser‐based powder bed fusion additive manufacturing systems on prosthetic device production. Environmental impacts due to manufacturing, use, and end of life of the designed solution were assessed. In addition, two powder production technologies, gas atomization (GA) and plasma atomization (PA), were compared in order to establish the most sustainable one. Production via traditional subtractive technologies and the additive manufacturing production were also compared. 3D building was found to have a significant environmental advantage compared to the traditional technology. The powder production process considerably influences on a damage point of view the additive manufacturing process; however, its impact can be mitigated if GA powders are employed.     

L-leucine stimulation of glucose uptake and utilization involves modulation of glucose – lipid metabolic switch and improved bioenergetic homeostasis in isolated rat psoas muscle ex vivo

Amino Acids - The antidiabetic effect of l-leucine has been attributed to its modulatory effect on glucose uptake and lipid metabolism in muscles. However, there is a dearth on its effect on...     

The acute systemic toxicity of thallium in rats produces oxidative stress: attenuation by metallothionein and Prussian blue

BioMetals - Thallium (TI) is one of the most toxic heavy metals. Human exposure to Tl occurs through contaminated drinking water and from there to food, a threat to health. Recently, environmental...     

Navigating from live to virtual social interactions: looking at but not manipulating smartphones provokes a spontaneous mimicry response in the observers

Journal of Ethology - By gathering data on people during their ordinary daily activities, we tested if looking at, but not manipulating, smartphones led to a mimicry response in the observer....     

Metabolomics and lipid profile analysis of Coccomyxa melkonianii SCCA 048

Extremophiles - With an unsupervised GC–MS metabolomics approach, polar metabolite changes of the microalgae Coccomyxa melkonianii SCCA 048 grown under standard conditions for seven weeks...     

Effect of membrane stiffness and cytoskeletal element density on mechanical stimuli within cells: an analysis of the consequences of ageing in cells

A finite element model of a single cell was created and used to compute the biophysical stimuli generated within a cell under mechanical loading. Major cellular components were incorporated in the model: the membrane, cytoplasm, nucleus, microtubules, actin filaments, intermediate filaments, nuclear lamina and chromatin. The model used multiple sets of tensegrity structures. Viscoelastic properties were assigned to the continuum components. To corroborate the model, a simulation of atomic force microscopy indentation was performed and results showed a force/indentation simulation with the range of experimental results. A parametric analysis of both increasing membrane stiffness (thereby modelling membrane peroxidation with age) and decreasing density of cytoskeletal elements (thereby modelling reduced actin density with age) was performed. Comparing normal and aged cells under indentation predicts that aged cells have a lower membrane area subjected to high strain as compared with young cells, but the difference, surprisingly, is very small and may not be measurable experimentally. Ageing is predicted to have a more significant effect on strain deep in the nucleus. These results show that computation of biophysical stimuli within cells are achievable with single-cell computational models; correspondence between computed and measured force/displacement behaviours provides a high-level validation of the model. Regarding the effect of ageing, the models suggest only small, although possibly physiologically significant, differences in internal biophysical stimuli between normal and aged cells.     

Oxidative stress,nitric oxide,endothelial dysfunction and tinnitus

To assess whether pathogenic endothelial dysfunction is involved in acute idiopathic tinnitus we enrolled 44 patients and 25 healthy volunteers. In blood from the internal jugular vein and brachial vein we determined malonaldehyde, 4-hydroxynonenal, mieloperoxidase, glutathione peroxidase, nitric oxide, l-arginine and l-ornitine, thrombomodulin (TM) and von Willebrand factor (vWF) activity during tinnitus and asymptomatic period.

Higher plasma concentrations of oxidative markers and l-arginine, and lower nitric oxide and l-ornitine levels were observed in jugular blood of patients with tinnitus, there being a significant difference between brachial and jugular veins. TM and vWF activity were significantly higher in patients' jugular blood than in brachial blood.

Our results suggest oxidant, TM, vWF activity production are increased and nitric oxide production reduced in brain circulation reflux blood of patients with acute tinnitus. These conditions are able to cause a general cerebro-vascular endothelial dysfunction, which in turn induce a dysfunction of microcirculation in the inner ear.