Ability to use the diazo dye, C.I. Acid Black 1 as a nitrogen source by the marine cyanobacterium Oscillatoria curviceps BDU92191

Ten different strains of marine cyanobacteria were tested for their ability to decolourise and degrade a recalcitrant diazo dye, C.I. Acid Black 1. Of them, Oscillatoria curvicepsBDU92191 was able to grow up to a tested concentration of 500 mG L⁻¹. The organism degraded 84% of the dye at 100 mG L⁻¹ in 8 days in a medium free of combined nitrogen. The dye degrading ability is attributed to the activities of the enzymes: laccase, polyphenol oxidase and azoreductase. The absence of the doublet amine peak in addition to the overall reduction of absorption in the IR spectra confirmed the mineralisation of the tested azo dye. The nitrogen assimilating enzyme studies along with nitrogenase assay strongly suggested the ability of the non-heterocystous, filamentous marine cyanobacterium, O. curvicepsBDU92191 to use C.I. Acid Black 1 as a nitrogen source in an oligotrophic environment.     

A wheat homolog of MOTHER OF FT AND TFL1 acts in the regulation of germination

Seed dormancy is an adaptive mechanism and an important agronomic trait. Temperature during seed development strongly affects seed dormancy in wheat (Triticum aestivum) with lower temperatures producing higher levels of seed dormancy. To identify genes important for seed dormancy, we used a wheat microarray to analyze gene expression in embryos from mature seeds grown at lower and higher temperatures. We found that a wheat homolog of MOTHER OF FT AND TFL1 (MFT) was upregulated after physiological maturity in dormant seeds grown at the lower temperature. In situ hybridization analysis indicated that MFT was exclusively expressed in the scutellum and coleorhiza. Mapping analysis showed that MFT on chromosome 3A (MFT-3A) colocalized with the seed dormancy quantitative trait locus (QTL) QPhs.ocs-3A.1. MFT-3A expression levels in a dormant cultivar used for the detection of the QTL were higher after physiological maturity; this increased expression correlated with a single nucleotide polymorphism in the promoter region. In a complementation analysis, high levels of MFT expression were correlated with a low germination index in T1 seeds. Furthermore, precocious germination of isolated immature embryos was suppressed by transient introduction of MFT driven by the maize (Zea mays) ubiquitin promoter. Taken together, these results suggest that MFT plays an important role in the regulation of germination in wheat.     

The caBIG® Life Science Business Architecture Model

MOTIVATION: Business Architecture Models (BAMs) describe what a business does, who performs the activities, where and when activities are performed, how activities are accomplished and which data are present. The purpose of a BAM is to provide a common resource for understanding business functions and requirements and to guide software development. The cancer Biomedical Informatics Grid (caBIG?) Life Science BAM (LS BAM) provides a shared understanding of the vocabulary, goals and processes that are common in the business of LS research. RESULTS: LS BAM 1.1 includes 90 goals and 61 people and groups within Use Case and Activity Unified Modeling Language (UML) Diagrams. Here we report on the model's current release, LS BAM 1.1, its utility and usage, and plans for future use and continuing development for future releases. Availability and Implementation: The LS BAM is freely available as UML, PDF and HTML (https://wiki.nci.nih.gov/x/OFNyAQ).     

Structure-activity determinants in antifungal plant defensins MsDef1 and MtDef4 with different modes of action against Fusarium graminearum

Plant defensins are small cysteine-rich antimicrobial proteins. Their three-dimensional structures are similar in that they consist of an α-helix and three anti-parallel β-strands stabilized by four disulfide bonds. Plant defensins MsDef1 and MtDef4 are potent inhibitors of the growth of several filamentous fungi including Fusarium graminearum. However, they differ markedly in their antifungal properties as well as modes of antifungal action. MsDef1 induces prolific hyperbranching of fungal hyphae, whereas MtDef4 does not. Both defensins contain a highly conserved γ-core motif (GXCX(3-9)C), a hallmark signature present in the disulfide-stabilized antimicrobial peptides, composed of β2 and β3 strands and the interposed loop. The γ-core motifs of these two defensins differ significantly in their primary amino acid sequences and in their net charge. In this study, we have found that the major determinants of the antifungal activity and morphogenicity of these defensins reside in their γ-core motifs. The MsDef1-γ4 variant in which the γ-core motif of MsDef1 was replaced by that of MtDef4 was almost as potent as MtDef4 and also failed to induce hyperbranching of fungal hyphae. Importantly, the γ-core motif of MtDef4 alone was capable of inhibiting fungal growth, but that of MsDef1 was not. The analysis of synthetic γ-core variants of MtDef4 indicated that the cationic and hydrophobic amino acids were important for antifungal activity. Both MsDef1 and MtDef4 induced plasma membrane permeabilization; however, kinetic studies revealed that MtDef4 was more efficient in permeabilizing fungal plasma membrane than MsDef1. Furthermore, the in vitro antifungal activity of MsDef1, MsDef1-γ4, MtDef4 and peptides derived from the γ-core motif of each defensin was not solely dependent on their ability to permeabilize the fungal plasma membrane. The data reported here indicate that the γ-core motif defines the unique antifungal properties of each defensin and may facilitate de novo design of more potent antifungal peptides.     

Engagement of overexpressed Her2 with GEP100 induces autonomous invasive activities and provides a biomarker for metastases of lung adenocarcinoma

Overexpression of Her2/ErbB2/Neu in cancer is often correlated with recurrent distant metastasis, although the mechanism still remains largely elusive. We have previously shown that EGFR, when tyrosine-phosphorylated, binds to GEP100/BRAG2 to activate Arf6, which induces cancer invasion and metastasis. We now show that overexpressed Her2 in lung adenocarcinoma cells also employs GEP100. Like EGFR-GEP100 binding, this association is primarily mediated by the pleckstrin homology (PH) domain of GEP100 and Tyr1139/Tyr1196 of Her2. Tyr1139/Tyr1196 are autonomously phosphorylated, when Her2 is overexpressed. Accordingly, invasive activities mediated by the Her2-GEP100 pathway are not dependent on external factors. Blocking Her2-GEP100 binding, as well as its signaling pathway all inhibit cancer invasive activities. Moreover, our clinical study indicates that co-overexpression of Her2 with GEP100 in primary lung adenocarcinomas of patients is correlated with the presence of their node-metastasis with a statistical significance. Since the GEP100 PH domain interacts with both Her2 and EGFR, targeting this domain may provide novel cancer therapeutics.     

Can plant defensins be used to engineer durable commercially useful fungal resistance in crop plants?

Plant defensins are cysteine-rich proteins that play an important role in defense against fungal pathogens. Because of their potent antifungal activity, they have a strong potential to be used for engineering disease resistance in crops. Significant advances have been made in elucidating their structure–activity relationships and modes of antifungal action. Their expression in transgenic plants provides resistance to fungal pathogens in crop plants. In this article, we review recent advances and offer future perspectives on the use of these proteins for engineering durable commercially useful disease resistance in transgenic crop plants.     

Genome-scale screen for DNA methylation-based detection markers for ovarian cancer

Background

The identification of sensitive biomarkers for the detection of ovarian cancer is of high clinical relevance for early detection and/or monitoring of disease recurrence. We developed a systematic multi-step biomarker discovery and verification strategy to identify candidate DNA methylation markers for the blood-based detection of ovarian cancer.

Methodology/Principal Findings

We used the Illumina Infinium platform to analyze the DNA methylation status of 27,578 CpG sites in 41 ovarian tumors. We employed a marker selection strategy that emphasized sensitivity by requiring consistency of methylation across tumors, while achieving specificity by excluding markers with methylation in control leukocyte or serum DNA. Our verification strategy involved testing the ability of identified markers to monitor disease burden in serially collected serum samples from ovarian cancer patients who had undergone surgical tumor resection compared to CA-125 levels.We identified one marker, IFFO1 promoter methylation (IFFO1-M), that is frequently methylated in ovarian tumors and that is rarely detected in the blood of normal controls. When tested in 127 serially collected sera from ovarian cancer patients, IFFO1-M showed post-resection kinetics significantly correlated with serum CA-125 measurements in six out of 16 patients.

Conclusions/Significance

We implemented an effective marker screening and verification strategy, leading to the identification of IFFO1-M as a blood-based candidate marker for sensitive detection of ovarian cancer. Serum levels of IFFO1-M displayed post-resection kinetics consistent with a reflection of disease burden. We anticipate that IFFO1-M and other candidate markers emerging from this marker development pipeline may provide disease detection capabilities that complement existing biomarkers.     

Donepezil, anti-Alzheimer's disease drug, prevents cardiac rupture during acute phase of myocardial infarction in mice

Background

We have previously demonstrated that the chronic intervention in the cholinergic system by donepezil, an acetylcholinesterase inhibitor, plays a beneficial role in suppressing long-term cardiac remodeling after myocardial infarction (MI). In comparison with such a chronic effect, however, the acute effect of donepezil during an acute phase of MI remains unclear. Noticing recent findings of a cholinergic mechanism for anti-inflammatory actions, we tested the hypothesis that donepezil attenuates an acute inflammatory tissue injury following MI.

Methods and Results

In isolated and activated macrophages, donepezil significantly reduced intra- and extracellular matrix metalloproteinase-9 (MMP-9). In mice with MI, despite the comparable values of heart rate and blood pressure, the donepezil-treated group showed a significantly lower incidence of cardiac rupture than the untreated group during the acute phase of MI. Immunohistochemistry revealed that MMP-9 was localized at the infarct area where a large number of inflammatory cells including macrophages infiltrated, and the expression and the enzymatic activity of MMP-9 at the left ventricular infarct area was significantly reduced in the donepezil-treated group.

Conclusion

The present study suggests that donepezil inhibits the MMP-9-related acute inflammatory tissue injury in the infarcted myocardium, thereby reduces the risk of left ventricular free wall rupture during the acute phase of MI.