Relative Susceptibility of Vitis vinifera Cultivars to Vector-Borne Xylella fastidiosa through Time

Understanding the interactions between pathogen, crop and vector are necessary for the development of disease control practices of vector-borne pathogens. For instance, resistant plant genotypes can help constrain disease symptoms due to infections and limit pathogen spread by vectors. On the other hand, genotypes susceptible to infection may increase pathogen spread owing to their greater pathogen quantity, regardless of their symptom status. In this study, we evaluated under greenhouse conditions the relative levels of resistance (i.e. relatively lower pathogen quantity) versus tolerance (i.e. less symptom severity) of 10 commercial grapevine (Vitis vinifera) cultivars to Pierce’s disease etiological agent, the bacterium Xylella fastidiosa. Overall, no correlation was detected between pathogen quantity and disease severity, indicating the existence of among-cultivar variation in plant response to infection. Thompson Seedless and Barbera were the two most susceptible among 10 evaluated cultivars. Rubired showed the least severe disease symptoms and was categorized as one of the most resistant genotypes in this study. However, within each cultivar the degree of resistance/tolerance was not consistent across sampling dates. These cultivar and temporal differences in susceptibility to infection may have important consequences for disease epidemiology and the effectiveness of management protocols.     

Adipocytokine Profile,Cytokine Levels and Foxp3 Expression in Multiple Sclerosis: a Possible Link to Susceptibility and Clinical Course of Disease

Background

Adipocytokines may be involved in multiple sclerosis (MS) as well as other autoimmune and inflammatory-related diseases. This study aims to compare levels of resistin, visfatin and leptin in three subgroups of MS patients with healthy subjects and also to study their relationship with Foxp3 expression and levels of several pro-inflammatory mediators such as interleukine-1 β(IL-1 β),tumor necrosis factor-α (TNF-α) and human sensitive C-reactive protein (hs-CRP).

Methods

A total of 391 subjects including 200 healthy controls and 191 MS patients were recruited for this case-control study. Circulating adipocytokines and inflammatory mediators were measured using immunoassay methods. Foxp3 gene expression in peripheral blood mononuclear cells (PBMC) was determined by quantitative real-time PCR. Fat tissue mass was evaluated by using dual energy X-ray absorptiometery (DEXA).

Results

A significant difference was observed in levels of inflammatory mediators, adipocytokines, Foxp3 gene expression and adipose tissue mass between MS patients and healthy controls. All adipocytokines were positively correlated with levels of inflammatory mediators and negatively correlated with Foxp3 expression in MS patients. In controls, there were positive correlations between circulating leptin and resistin with TNF-α and IL-1β in subgroup analysis, the highest levels of TNF-α, IL-1β, hs-CRP, resistin and leptin were observed in primary progressive-MS (PP-MS) patients. Also, expression of Foxp3 and levels of visfatin in relapsing remitting-MS(RR-MS) patients were higher compared with the other subgroups.

Conclusions

Our findings suggest the potential role of adipocytokines in pathogenesis and severity of MS. Notably, the relationship of adipocytokines levels with inflammatory cytokines as well as clinical features of MS could be considerable in translational medicine and biomarker studies.     

Anticancer and apoptotic activities of parthenolide in combination with epirubicin in mda-mb-468 breast cancer cells

Molecular Biology Reports - Breast cancer is the most common malignancy in women worldwide. Unfortunately, current therapeutic methods are not completely efficient. Hence, combination therapy with...     

SLC26 anion exchangers of guinea pig pancreatic duct: molecular cloning and functional characterization

The secretin-stimulated human pancreatic duct secretes HCO(3)(-)-rich fluid essential for normal digestion. Optimal stimulation of pancreatic HCO(3)(-) secretion likely requires coupled activities of the cystic fibrosis transmembrane regulator (CFTR) anion channel and apical SLC26 Cl(-)/HCO(3)(-) exchangers. However, whereas stimulated human and guinea pig pancreatic ducts secrete ～140 mM HCO(3)(-) or more, mouse and rat ducts secrete ～40-70 mM HCO(3)(-). Moreover, the axial distribution and physiological roles of SLC26 anion exchangers in pancreatic duct secretory processes remain controversial and may vary among mammalian species. Thus the property of high HCO(3)(-) secretion shared by human and guinea pig pancreatic ducts prompted us to clone from guinea pig pancreatic duct cDNAs encoding Slc26a3, Slc26a6, and Slc26a11 polypeptides. We then functionally characterized these anion transporters in Xenopus oocytes and human embryonic kidney (HEK) 293 cells. In Xenopus oocytes, gpSlc26a3 mediated only Cl(-)/Cl(-) exchange and electroneutral Cl(-)/HCO(3)(-) exchange. gpSlc26a6 in Xenopus oocytes mediated Cl(-)/Cl(-) exchange and bidirectional exchange of Cl(-) for oxalate and sulfate, but Cl(-)/HCO(3)(-) exchange was detected only in HEK 293 cells. gpSlc26a11 in Xenopus oocytes exhibited pH-dependent Cl(-), oxalate, and sulfate transport but no detectable Cl(-)/HCO(3)(-) exchange. The three gpSlc26 anion transporters exhibited distinct pharmacological profiles of (36)Cl(-) influx, including partial sensitivity to CFTR inhibitors Inh-172 and GlyH101, but only Slc26a11 was inhibited by PPQ-102. This first molecular and functional assessment of recombinant SLC26 anion transporters from guinea pig pancreatic duct enhances our understanding of pancreatic HCO(3)(-) secretion in species that share a high HCO(3)(-) secretory output.     

Alpha-synuclein interacts with Glucocerebrosidase providing a molecular link between Parkinson and Gaucher diseases

The presynaptic protein α-synuclein (α-syn), particularly in its amyloid form, is widely recognized for its involvement in Parkinson disease (PD). Recent genetic studies reveal that mutations in the gene GBA are the most widespread genetic risk factor for parkinsonism identified to date. GBA encodes for glucocerebrosidase (GCase), the enzyme deficient in the lysosomal storage disorder, Gaucher disease (GD). In this work, we investigated the possibility of a physical linkage between α-syn and GCase, examining both wild type and the GD-related N370S mutant enzyme. Using fluorescence and nuclear magnetic resonance spectroscopy, we determined that α-syn and GCase interact selectively under lysosomal solution conditions (pH 5.5) and mapped the interaction site to the α-syn C-terminal residues, 118-137. This α-syn-GCase complex does not form at pH 7.4 and is stabilized by electrostatics, with dissociation constants ranging from 1.2 to 22 μm in the presence of 25 to 100 mm NaCl. Intriguingly, the N370S mutant form of GCase has a reduced affinity for α-syn, as does the inhibitor conduritol-β-epoxide-bound enzyme. Immunoprecipitation and immunofluorescence studies verified this interaction in human tissue and neuronal cell culture, respectively. Although our data do not preclude protein-protein interactions in other cellular milieux, we suggest that the α-syn-GCase association is favored in the lysosome, and that this noncovalent interaction provides the groundwork to explore molecular mechanisms linking PD with mutant GBA alleles.     

Reassessment of the environmental model of developmental polyphenism in spadefoot toad tadpoles

Polyphenism is the expression of multiple, discrete phenotypes from one genotype, and understanding the environmental factors that trigger development of alternative phenotypes is a critical step toward understanding the evolution of polyphenism and its developmental control. While much is known about the ecology of the well-known carnivore/omnivore polyphenism in spadefoot toad tadpoles, the environmental cues for the development of the specialized carnivore phenotype are not completely clear. We examined 27 different experimental treatments in two spadefoot toad species and used over 1,000 tadpoles in an attempt to elucidate those cues. While only 44 carnivores developed in these treatments, they were concentrated at cooler water temperatures and a diet that included fairy shrimp. However, while a diet of fairy shrimp promoted carnivore development, it was not necessary for inducing carnivore development at lower and intermediate water temperatures. Evidence also suggested a role for social inhibition that limited the proportion of interacting tadpoles that become carnivores. Tadpoles of Spea multiplicata grew larger at cooler temperatures and larger when their diets included fairy shrimp, whereas tadpoles of S. bombifrons grew larger at warmer temperatures and when their diets did not include fairy shrimp. These results indicate that carnivore induction can occur through different cues and that our current model for carnivore development is too limited. Finally, we argue that the carnivore/omnivore spadefoot system is neither a polyphenism nor a polymorphism but is a continuously distributed plasticity.     

Protein folding kinetics provides a context-independent assessment of beta-strand propensity in the Fyn SH3 domain

Structural database-derived propensities for amino acids to adopt particular local protein structures, such as alpha-helix and beta-strand, have long been recognized and effectively exploited for the prediction of protein secondary structure. However, the experimental verification of database-derived propensities using mutagenesis studies has been problematic, especially for beta-strand propensities, because local structural preferences are often confounded by non-local interactions arising from formation of the native tertiary structure. Thus, the overall thermodynamic stability of a protein is not always altered in a predictable manner by changes in local structural propensity at a single position. In this study, we have undertaken an investigation of the relationship between beta-strand propensity and protein folding kinetics. By characterizing the effects of a wide variety of amino acid substitutions at two different beta-strand positions in an SH3 domain, we have found that the observed changes in protein folding rates are very well correlated to beta-strand propensities for almost all of the substitutions examined. In contrast, there is little correlation between propensities and unfolding rates. These data indicate that beta-strand conformation is well formed in the structured portion of the SH3 domain transition state, and that local structure propensity strongly influences the stability of the transition state. Since the transition state is known to be packed more loosely than the native state and likely lacks many of the non-local stabilizing interactions seen in the native state, we suggest that folding kinetics studies may generally provide an effective means for the experimental validation of database-derived local structural propensities.     

Computational design of the Fyn SH3 domain with increased stability through optimization of surface charge charge interactions

Computational design of surface charge-charge interactions has been demonstrated to be an effective way to increase both the thermostability and the stability of proteins. To test the robustness of this approach for proteins with predominantly beta-sheet secondary structure, the chicken isoform of the Fyn SH3 domain was used as a model system. Computational analysis of the optimal distribution of surface charges showed that the increase in favorable energy per substitution begins to level off at five substitutions; hence, the designed Fyn sequence contained four charge reversals at existing charged positions and one introduction of a new charge. Three additional variants were also constructed to explore stepwise contributions of these substitutions to Fyn stability. The thermodynamic stabilities of the variants were experimentally characterized using differential scanning calorimetry and far-UV circular dichroism spectroscopy and are in very good agreement with theoretical predictions from the model. The designed sequence was found to have increased the melting temperature, DeltaT (m) = 12.3 +/- 0.2 degrees C, and stability, DeltaDeltaG(25 degrees C) = 7.1 +/- 2.2 kJ/mol, relative to the wild-type protein. The experimental data suggest that a significant increase in stability can be achieved through a very small number of amino acid substitutions. Consistent with a number of recent studies, the presented results clearly argue for a seminal role of surface charge-charge interactions in determining protein stability and suggest that the optimization of surface interactions can be an attractive strategy to complement algorithms optimizing interactions in the protein core to further enhance protein stability.     

Biodegradation of Aliphatic and Aromatic Fractions of Heavy Crude Oil-Contaminated Soil: A Pilot Study

Crude oil is one of the major contaminants of soil and water. Biodegradation is a good option for reducing oil contamination in soil. Soil fertilizers can help the microorganisms biodegrade oil with higher efficiency. In this study, the effect of chemical fertilizers and animal manure on crude oil reduction was compared and the reduction of the aliphatic and aromatic fractions was studied during 8 months. The higher reduction of crude oil (54%) was observed in tests containing chemical fertilizers and wood chips, followed by those containing animal manure (46%). The reduction of aliphatic and aromatic fractions was also higher in fertilized tests. Our results showed that in the experiments with mixed chemical fertilizers and wood chips, the reduction of crude oil and its aliphatic and aromatic fractions was higher than the experiments with only chemical fertilizers and those with animal manure. The reductions in the experiments with animal manure, however, were higher than those with only chemical fertilizers.     

Plant growth-promoting bacteria (PGPBs) and copper (II) oxide (CuO) nanoparticle ameliorates DNA damage and DNA Methylation in wheat (Triticum aestivum L.) exposed to NaCl stress

Journal of Plant Biochemistry and Biotechnology - Wheat is the second important cereal crop worldwide due to nutritional composition and role in meeting daily energy needs. Salinity is an abiotic...