Global genetic diversity of Aedes aegypti

Mosquitoes, especially Aedes aegypti, are becoming important models for studying invasion biology. We characterized genetic variation at 12 microsatellite loci in 79 populations of Ae. aegypti from 30 countries in six continents, and used them to infer historical and modern patterns of invasion. Our results support the two subspecies Ae. aegypti formosus and Ae. aegypti aegypti as genetically distinct units. Ae. aegypti aegypti populations outside Africa are derived from ancestral African populations and are monophyletic. The two subspecies co‐occur in both East Africa (Kenya) and West Africa (Senegal). In rural/forest settings (Rabai District of Kenya), the two subspecies remain genetically distinct, whereas in urban settings, they introgress freely. Populations outside Africa are highly genetically structured likely due to a combination of recent founder effects, discrete discontinuous habitats and low migration rates. Ancestral populations in sub‐Saharan Africa are less genetically structured, as are the populations in Asia. Introduction of Ae. aegypti to the New World coinciding with trans‐Atlantic shipping in the 16th to 18th centuries was followed by its introduction to Asia in the late 19th century from the New World or from now extinct populations in the Mediterranean Basin. Aedes mascarensis is a genetically distinct sister species to Ae. aegypti s.l. This study provides a reference database of genetic diversity that can be used to determine the likely origin of new introductions that occur regularly for this invasive species. The genetic uniqueness of many populations and regions has important implications for attempts to control Ae. aegypti, especially for the methods using genetic modification of populations.     

Elucidating the role of oxidative stress in the therapeutic effect of rutin on experimental acute pancreatitis

Introduction: Acute pancreatitis (AP) may be severe and cause hospitalization or death, and the available treatment is insufficient to control pancreatic inflammation and pain. Rutin is a natural flavonoid with the potential to treat AP via anti-inflammatory, antinociceptive, and antioxidant activities.

Aim: This study investigated the beneficial effects of rutin on experimental AP induced by l-arginine administration in mice.

Methods: The l-arginine-induced AP model was used in Swiss mice (n?=?6–8). Mice submitted to AP induction were treated with rutin (37.5, 75, or 150?mg kg^?1, p.o.) or vehicle (saline) after 24, 36, 48, and 60?h of AP induction. Abdominal hyperalgesia, serum enzymes, interleukin (IL)-6 levels, pancreatic inflammatory parameters, malondialdehyde (MDA) levels, antioxidant enzyme activities, and 3-nitrotyrosine contents were measured 72?h after induction.

Results: Mice submitted to l-arginine injections developed abdominal hyperalgesia and increased serum amylase, lipase, C-reactive protein and IL-6 concentrations; and increased pancreatic myeloperoxidase activity, edema index, MDA, and 3-nitrotyrosine contents. A marked decrease in catalase activity was observed in the pancreas without alterations of superoxide dismutase (SOD) activity compared with the control group. Rutin treatment significantly impaired all the parameters that were altered by AP induction, but increased catalase and SOD activities in the pancreas compared with the vehicle-treated group.

Conclusion: Rutin treatment exerted a protective effect on l-arginine-induced AP by mechanisms involving the reduction of oxidative stress, which suggests that this flavonoid has a potential for future approaches designed for the management of AP.     

Novel flow cytometric approach for the detection of adipocyte subpopulations during adipogenesis

The ability of mesenchymal stromal cells (MSCs) to differentiate into adipocytes provides a cellular model of human origin to study adipogenesis in vitro. One of the major challenges in studying adipogenesis is the lack of tools to identify and monitor the differentiation of various subpopulations within the heterogeneous pool of MSCs. Cluster of differentiation (CD)36 plays an important role in the formation of intracellular lipid droplets, a key characteristic of adipocyte differentiation/maturation. The objective of this study was to develop a reproducible quantitative method to study adipocyte differentiation by comparing two lipophilic dyes [Nile Red (NR) and Bodipy 493/503] in combination with CD36 surface marker staining. We identified a subpopulation of adipose-derived stromal cells that express CD36 at intermediate/high levels and show that combining CD36 cell surface staining with neutral lipid-specific staining allows us to monitor differentiation of adipose-derived stromal cells that express CD36^{intermediate/high} during adipocyte differentiation in vitro. The gradual increase of CD36^{intermediate/high/}NR^positive cells during the 21 day adipogenesis induction period correlated with upregulation of adipogenesis-associated gene expression.     

Characterization of the antioxidant activity of aglycone and glycosylated derivatives of hesperetin: an in vitro and in vivo study

The flavonoids are mainly present in Citrus fruits as their glycosyl derivatives. This study was conducted comparing in vitro xanthine oxidase inhibitory activity of the aglycone hesperetin and its glycosylated forms (hesperidin and G‐hesperidin) and their effects on the plasma lipid profile and the oxidative–antioxidative system (TBARS and antioxidant enzymes) in rats. The concentrations of the major conjugated metabolites in rat plasma after oral administration of these compounds were also determined. Wistar male rats were randomly assigned to three groups (n = 6) supplemented for 30 days with 1 mmol/kg body mass of hesperetin, hesperidin or G‐hesperidin. Hesperetin was a stronger xanthine oxidase inhibitor (IC₅₀ = 53 μM and K_i = 17.3 μM) than the glycosylate derivatives. Supplementation with the three compounds led to a lower (more favorable) atherogenic index, and an antioxidant preventive effect from the increase of hepatic superoxide dismutase was observed associated to HT supplementation, possibly because of the higher level of hesperetin‐glucuronide in rat plasma. Copyright © 2015 John Wiley & Sons, Ltd.     

Phenotypic traits of the Mediterranean <Emphasis Type="Italic">Phragmites australis</Emphasis> M1 lineage: differences between the native and introduced ranges

The environmental conditions in the new ranges of introduced plant species are often different from the conditions in their native ranges, and invasive plant species have been assumed to adapt to different environmental conditions by rapid ecological evolution in the invasive range after the introduction. Another interpretation of the change in plant traits after their introduction, however, is ecological fitting, which is based on the inherently high phenotypic plasticity of the species rather than on evolution. The Mediterranean haplotype M1 lineage of the wetland grass Phragmites australis was introduced to the coastal wetlands along the Gulf Coast of North America, where it is exposed to a different climate compared to its original range. The climate in the native range is arid or temperate with dry and hot summers, whereas the climate in the introduced range is warmer and has a higher and more uniform precipitation than that in the native range. This warmer and more humid environment is likely to pose different selection pressures to the plants in the introduced range and thus cause rapid evolutionary change and phenotypic differentiation in the introduced range. Here, we compared phenotypic traits of the M1 lineage from the native and introduced ranges in a common garden experiment to study the processes assisting the successful spread in the introduced range. Overall, the native and introduced groups were similar, but we detected a few phenotypic traits that diverged. Ecological fitting could be the fundamental mechanism by which the P. australis M1 lineage survives and spreads in the introduced Gulf Coast region. However, further research is needed to assess how the diverging traits observed in our study in Denmark (lower photosynthetic rates, lower chlorophylls concentration and higher leaf K concentration for the introduced than for the native genotypes) are expressed in the two ranges.     

Structure of the Na,K-ATPase regulatory protein FXYD1 in micelles

FXYD1 is a major regulatory subunit of the Na,K-ATPase and the principal substrate of hormone-regulated phosphorylation by c-AMP dependent protein kinases A and C in heart and skeletal muscle sarcolemma. It is a member of an evolutionarily conserved family of membrane proteins that regulate the function of the enzyme complex in a tissue-specific and physiological-state-specific manner. Here, we present the three-dimensional structure of FXYD1 determined in micelles by NMR spectroscopy. Structure determination was made possible by measuring residual dipolar couplings in weakly oriented micelle samples of the protein. This allowed us to obtain the relative orientations of the helical segments and information about the protein dynamics. The structural analysis was further facilitated by the inclusion of distance restraints, obtained from paramagnetic spin label relaxation enhancements, and by refinement with a micelle depth restraint, derived from paramagnetic Mn line broadening effects. The structure of FXYD1 provides the foundation for understanding its intra-membrane association with the Na,K-ATPase alpha subunit and suggests a mechanism whereby the phosphorylation of conserved Ser residues, by protein kinases A and C, could induce a conformational change in the cytoplasmic domain of the protein to modulate its interaction with the alpha subunit.