Neuronal ribonucleoprotein granules: Dynamic sensors of localized signals

Membrane‐less organelles, because of their capacity to dynamically, selectively and reversibly concentrate molecules, are very well adapted for local information processing and rapid response to environmental fluctuations. These features are particularly important in the context of neuronal cells, where synapse‐specific activation, or localized extracellular cues, induce signaling events restricted to specialized axonal or dendritic subcompartments. Neuronal ribonucleoprotein (RNP) particles, or granules, are nonmembrane bound macromolecular condensates that concentrate specific sets of mRNAs and regulatory proteins, promoting their long‐distance transport to axons or dendrites. Neuronal RNP granules also have a dual function in regulating the translation of associated mRNAs: while preventing mRNA translation at rest, they fuel local protein synthesis upon activation. As revealed by recent work, rapid and reversible switches between these two functional modes are triggered by modifications of the networks of interactions underlying RNP granule assembly. Such flexible properties also come with a cost, as neuronal RNP granules are prone to transition into pathological aggregates in response to mutations, aging, or cellular stresses, further emphasizing the need to better understand the mechanistic principles governing their dynamic assembly and regulation in living systems.     

Can We Identify the Active Ingredients of Behaviour Change Interventions for Coronary Heart Disease Patients? A Systematic Review and Meta-Analysis

BackgroundThe main behaviour change intervention available for coronary heart disease (CHD) patients is cardiac rehabilitation. There is little recognition of what the active ingredients of behavioural interventions for CHD might be. Using a behaviour change technique (BCT) framework to code existing interventions may help to identify this. The objectives of this systematic review are to determine the effectiveness of CHD behaviour change interventions and how this may be explained by BCT content and structure.ConclusionsBehaviour change interventions for CHD patients appear to have a positive impact on a number of outcomes. Using an existing BCT taxonomy to code the interventions helped us to understand which were the most commonly used techniques, providing information and goal setting, but not the active components of these complex interventions.     

A Simple and Fast Non-Radioactive Bridging Immunoassay for Insulin Autoantibodies

Type 1 diabetes (T1D) is an autoimmune disease which results from the destruction of pancreatic beta cells. Autoantibodies directed against islet antigens are valuable diagnostic tools. Insulin autoantibodies (IAAs) are usually the first to appear and also the most difficult to detect amongst the four major islet autoantibodies. A non-radioactive IAA bridging ELISA was developed to this end. In this assay, one site of the IAAs from serum samples is bound to a hapten-labeled insulin (GC300-insulin), which is subsequently captured on anti-GC300 antibody-coated 96-well plates. The other site of the IAAs is bound to biotinylated insulin, allowing the complex to be detected by an enzyme-streptavidin conjugate. In the present study, 50 serum samples from patients with newly diagnosed T1D and 100 control sera from non-diabetic individuals were analyzed with our new assay and the results were correlated with an IAA radioimmunoassay (RIA). Using IAA bridging ELISA, IAAs were detected in 32 out of 50 T1D children, whereas with IAA RIA, 41 out of 50 children with newly diagnosed T1D were scored as positive. In conclusion, the IAA bridging ELISA could serve as an attractive approach for rapid and automated detection of IAAs in T1D patients for diagnostic purposes.     

Imaging cell interactions with native and crosslinked polyelectrolyte multilayers

The adhesion of primary chondrocytes to polyelectrolyte multilayer films, made of poly(l-lysine) (PLL) and hyaluronan (HA), was investigated for native and crosslinked films, either ending by PLL or HA. Crosslinking the film was achieved by means of a water-soluble carbodiimide in combination with N-hydroxysulfosuccinimide. The adhesion of macrophages and primary chondrocytes was investigated by microscopical techniques (optical, confocal, and atomic), providing useful information on the cell/film interface. Native films were found to be nonadhesive for the, primary chondrocytes, but could be degraded by macrophages, as could be visualized by confocal laser scanning microscopy after film labeling. Confocal microscopy images show that these films can be deformed by the condrocytes and that PLL diffuses at the chondrocyte membrane. In contrast, the cells adhered and proliferated well on the crosslinked films, which were not degraded by the macrophages. These results were confirmed by a MTT test over a 6-d period and by atomic force microscopy observations. We thus prove that chemical crosslinking can dramatically change cell adhesion properties, the cells being more stably anchored on the crosslinked films. Both authors kcontributed equally.     

Antimicrobial peptides from the skin of the Tsushima brown frog Rana tsushimensis

The Tsushima brown frog Rana tsushimensis Stejneger, 1907 exists in reproductive isolation on the island of Tsushima, Japan. Six peptides with antimicrobial activity were isolated in pure form from an extract of the skin of this species and their amino acid sequences identified them as members of the brevinin-1 (one peptide), brevinin-2 (one peptide) and temporin (four peptides) families. The C-terminally alpha-amidated brevinin-1 peptide (FLGSIVGALASALPSLISKIRN.NH2) lacks the cyclic heptapeptide domain Cys18-(Xaa)4-Lys-Cys24 at the COOH-terminus of the molecule that characterizes other members of that family. A structurally similar brevinin-1 peptide, also lacking the cyclic domain, was previously isolated from the skin of the Ryukyu brown frog Rana okinavana, indicative of a close phylogenetic relationship between the species. Brevinin-2TSa (GIMSLFKGVLKTAGKHVAGSLVDQLKCKITGGC) showed broad-spectrum growth inhibitory activity against a range of Gram-negative and Gram-positive bacteria (including methicillin-resistant Staphylococcus aureus) (minimum inhibitory concentrations< or =25 microM) and relatively low hemolytic activity against human erythrocytes (LD50=100 microM). The peptide therefore represents a candidate for drug development.     

Multiple vector-borne pathogens of domestic animals in Egypt

Vector Borne Diseases (VBDs) are considered emerging and re-emerging diseases that represent a global burden. The aim of this study was to explore and characterize vector-borne pathogens in different domestic animal hosts in Egypt. A total of 557 blood samples were collected from different animals using a convenience sampling strategy (203 dogs, 149 camels, 88 cattle, 26 buffaloes, 58 sheep and 33 goats). All samples were tested for multiple pathogens using quantitative PCR and standard PCR coupled with sequencing. We identified Theileria annulata and Babesia bigemina in cattle (15.9 and 1.1%, respectively), T. ovis in sheep and buffaloes (8.6 and 7.7%, respectively) and Ba. canis in dogs (0.5%) as well as Anaplasma marginale in cattle, sheep and camels (20.4, 3.4 and 0.7%, respectively) and Coxiella burnetii in sheep and goats (1.7 and 3%; respectively). New genotypes of An. centrale, An. ovis, An. platys-like and Borrelia theileri were found in cattle (1.1,3.4, 3.4 and 3.4%, respectively), An. platys-like in buffaloes (7.7%), An. marginale, An. ovis, An. platys-like and Bo. theileri in sheep (3.4, 1.7, 1.7 and 3.4%, respectively), An. platys, An. platys-like and Setaria digitata in camels (0.7, 5.4 and 0.7%, respectively) and Rickettsia africae-like, An. platys, Dirofilaria repens and Acanthocheilonema reconditum in dogs (1.5, 3.4, 1 and 0.5%, respectively). Co-infections were found in cattle, sheep and dogs (5.7, 1.7, 0.5%, respectively). For the first time, we have demonstrated the presence of several vector-borne zoonoses in the blood of domestic animals in Egypt. Dogs and ruminants seem to play a significant role in the epidemiological cycle of VBDs.     

Hydraulic redistribution: limitations for plants in saline soils

Hydraulic redistribution (HR), the movement of water from wet to dry patches in the soil via roots, occurs in different ecosystems and plant species. By extension of the principle that HR is driven by gradients in soil water potential, HR has been proposed to occur for plants in saline soils. Despite the inherent spatial patchiness and salinity gradients in these soils, the lack of direct evidence of HR in response to osmotic gradients prompted us to ask the question: are there physical or physiological constraints to HR for plants in saline environments? We propose that build‐up of ions in the root xylem sap and in the leaf apoplast, with the latter resulting in a large predawn disequilibrium of water potential in shoots compared with roots and soil, would both impede HR. We present a conceptual model that illustrates how processes in root systems in heterogeneous salinity with water potential gradients, even if equal to those in non‐saline soils, will experience a dampened magnitude of water potential gradients in the soil–plant continuum, minimizing or preventing HR. Finally, we provide an outlook for understanding the relevance of HR for plants in saline environments by addressing key research questions on plant salinity tolerance.     

WOX14 promotes bioactive gibberellin synthesis and vascular cell differentiation in Arabidopsis

Procambial and cambial stem cells provide the initial cells that allow the formation of vascular tissues. WOX4 and WOX14 have been shown to act redundantly to promote procambial cell proliferation and differentiation. Gibberellins (GAs), which have an important role in wood formation, also stimulate cambial cell division. Here we show that the loss of WOX14 function phenocopies some traits of GA‐deficient mutants that can be complemented by exogenous GA application, whereas WOX14 overexpression stimulates the expression of GA3ox anabolism genes and represses GA2ox catabolism genes, promoting the accumulation of bioactive GA. More importantly, our data clearly indicate that WOX14 but not WOX4 promotes vascular cell differentiation and lignification in inflorescence stems of Arabidopsis.