The N-BAR domain protein,Bin3, regulates Rac1- and Cdc42-dependent processes in myogenesis

Actin dynamics are necessary at multiple steps in the formation of multinucleated muscle cells. BAR domain proteins can regulate actin dynamics in several cell types, but have been little studied in skeletal muscle. Here, we identify novel functions for the N-BAR domain protein, Bridging integrator 3 (Bin3), during myogenesis in mice. Bin3 plays an important role in regulating myofiber size in vitro and in vivo. During early myogenesis, Bin3 promotes migration of differentiated muscle cells, where it colocalizes with F-actin in lamellipodia. In addition, Bin3 forms a complex with Rac1 and Cdc42, Rho GTPases involved in actin polymerization, which are known to be essential for myotube formation. Importantly, a Bin3-dependent pathway is a major regulator of Rac1 and Cdc42 activity in differentiated muscle cells. Overall, these data classify N-BAR domain proteins as novel regulators of actin-dependent processes in myogenesis, and further implicate BAR domain proteins in muscle growth and repair.     

A single origin for the limnetic–euryhaline taxa in the Corbulidae (Bivalvia)

The bivalve family Corbulidae, known colloquially as ‘basket clams’, includes species tolerating a wide variety of habitats ranging from open marine to freshwater. Previous studies of corbulid phylogenetics have been based mainly on shell morphology and to some extent soft tissue anatomy. However, these studies have been inadequate for corbulid classification because of difficulties in determining the inter‐relationships of primarily marine species with non‐marine species, the latter commonly exhibiting highly divergent morphological, ecological and environmental characteristics from their marine counterparts. The first molecular phylogenetic study of the Corbulidae is presented herein, analysing DNA sequences from the 18S rRNA and 28S rRNA genes, separately and in combination. Fifteen corbulid species and 14 outgroup taxa were included in the analyses. Corbulidae is resolved as monophyletic, comprising three groups with varying support. The non‐marine species form one group that we name as the subclade ‘limnetic–euryhaline Corbulidae’ (LEC) and comprising the genera Lentidium, Erodona and Potamocorbula. This LEC, which is consistently recovered as monophyletic, is globally distributed. The marine Corbulidae are divided into two well‐supported lineages in combined analyses although there are inconsistencies in their membership between single‐gene analyses. One of the two lineages consists of primarily Western Pacific taxa and the other of North American and Caribbean taxa. Finally, the authors advocate further study on the LEC to mitigate potential biological invasions beyond their native distribution.     

Schistosoma mansoni: In vitro schistosomicidal activity of essential oil of Baccharis trimera (less) DC

Schistosomiasis is a chronic parasitic disease caused by the trematode species Schistosoma mansoni. Chemotherapy is the only immediate recourse to minimize the prevalence and incidence of this disease worldwide. At present, praziquantel (PZQ) is the drug of choice for the treatment of all forms of schistosomiasis. However, dependence on a single drug is concern because some strains can become resistant. In this context, medicinal plants become potential candidates as sources of new drug prototypes. This study provides findings on the schistosomicidal activity of the essential oil of Baccharis trimera in in vitro assays. During the assays parameters such as motility of adult worms, oviposition, morphological changes on the tegument and especially the mortality rate of adult worms of the BH strain were evaluated. The assays, which were carried out with four concentrations - 24, 48, 91 and 130μg/mL - of the essential oil, have shown a promising activity regarding the parameters under study. It was possible to notice a significant decline in the motility of the worms and a mortality rate of 100% 30h after they had been exposed to the essential oil in the concentration of 130μg/mL. Male worms were more susceptible, producing a dose-response effect within a smaller exposition period than female worms. In what refers to morphological changes, the essential oil of B. trimera induced a peeling on the tegument surface, as well as the destruction of tubercles and spines, which resulted in smooth areas on the body surface. The essential oil also caused tegument destruction in female worms, in addition to destruction of the oral and acetabular suckers. It is the first time that the schistosomicidal activity has been reported for essential oil of B. trimera (less) DC.     

Interaction of piroxicam with bovine serum albumin investigated by spectroscopic,calorimetric and computational molecular methods

Abstract

The binding of drugs to serum proteins is governed by weak non-covalent forces. In this study, the nature and magnitude of the interactions between piroxicam (PRX) and bovine serum albumin (BSA) was assessed using spectroscopic, calorimetric and computational molecular methods. The fluorescence data revealed an atypical behavior during PRX and BSA interaction. The quenching process of tryptophan (Trp) by PRX is a dual one (approximately equal static and dynamic quenched components). The FRET results indicate that a non-radiative transfer of energy occurred. The association constant and the number of binding sites indicate moderate PRX and BSA binding. The competitive binding study indicates that PRX is bound to site I from the hydrophobic pocket of subdomain IIA of BSA. The synchronous spectra showed that the microenvironment around the BSA fluorophores and protein conformation do not change considerably. The Trp lifetimes revealed that PRX mainly quenches the fluorescence of Trp-213 situated in the hydrophobic domain. The CD and DSC investigation show that addition of PRX stabilizes the protein structure. ITC results revealed that BSA-PRX binding involves a combination of electrostatic, hydrophobic and hydrogen interactions. The analysis of the computational data is consistent with the experimental results. This thorough investigation of the PRX-BSA binding may provide support for other studies concerning moderate affinity drugs with serum protein.

Communicated by Ramaswamy H. Sarma     

Elicitation Improves the Leaf Area,Enzymatic Activities,Antioxidant Activity and Content of Secondary Metabolites in Achillea millefolium L. Grown in the Field

Salicylic acid (SA) is a plant hormone that stimulates the growth and metabolism of plants, also acting as an abiotic elicitor. This study aimed to evaluate the effect of SA on leaf production, leaf area and synthesis of secondary compounds in yarrow plants. The experiments were conducted under field conditions in two consecutive years and f-received SA foliar applications (T1-control; T2-1.0 mmol L⁻¹ applications at 20, 60 and 100 days after planting (DAP) and T3-1.0 mmol L⁻¹ applications at 100 DAP during 3 days). The exogenous application of SA resulted in increases in leaf area (total and specific), number of leaves and leaf mass ratio of yarrow plants, polyphenolic compounds, phenylalanine ammonia-lyase and chalcone synthase enzymes and the antioxidant activity of the plant extract. The HPLC–DAD–MS/MS analysis of phenolic compounds revealed increases in the amounts of quinic acid and rutin. The results of this research lead us to affirm that SA exerted both the hormonal effect on number of leaves and leaf area, and also acted as eliciting substance.

     

A taxonomy of transcriptomic cell types across the isocortex and hippocampal formation

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Interaction between N-dodecyl-N,N-dimethyl-N-benzylammonium halides and phosphatidylcholine bilayers-the effect of counterions

The interaction of N-dodecyl-N,N-dimethyl-N-benzylammonium halides (DBeAX) with two types of phospholipid vesicles (MLV and SUV) was investigated using DSC and 1H NMR. It was suggested that the benzyl group like the micellisation process (J. Colloid Interface Sci. 218 (1999) 529) changes its position when interacting with phosphatidylcholine bilayers and incorporates into the bilayer. In order to enhance counterion-water interactions, the surfactants were added either to the water phase or directly to the lipid phase (a mixed film was formed). It follows from the obtained results that for both types of liposomes and both manners in which the surfactant was added, the interaction of DBeAX with liposomes and consequent changes in the phospholipid bilayer organisation depend on the kind of counterion. Results are discussed in terms of counterion ability to modify water structure.