Phospholipase Dε enhances Braasca napus growth and seed production in response to nitrogen availability

Phospholipase D (PLD), which hydrolyses phospholipids to produce phosphatidic acid, has been implicated in plant response to macronutrient availability in Arabidopsis. This study investigated the effect of increased PLDε expression on nitrogen utilization in Brassica napus to explore the application of PLDε manipulation to crop improvement. In addition, changes in membrane lipid species in response to nitrogen availability were determined in the oil seed crop. Multiple PLDε over expression (PLDε‐OE) lines displayed enhanced biomass accumulation under nitrogen‐deficient and nitrogen‐replete conditions. PLDε‐OE plants in the field produced more seeds than wild‐type plants but have no impact on seed oil content. Compared with wild‐type plants, PLDε‐OE plants were enhanced in nitrate transporter expression, uptake and reduction, whereas the activity of nitrite reductase was higher under nitrogen‐depleted, but not at nitrogen‐replete conditions. The level of nitrogen altered membrane glycerolipid metabolism, with greater impacts on young than mature leaves. The data indicate increased expression of PLDε has the potential to improve crop plant growth and production under nitrogen‐depleted and nitrogen‐replete conditions.     

A step through the looking glass

正Despite our many advances in deconstructing and understanding cellular and biomolecular machineries,the homochirality of life remains an enigma.Since our earliest ancestors,the central dogma has operated solely on D-DNA     

A group matrix representation relevant to scales of measurement of clinical disease states via stratified vectors

Background

Previously, we applied basic group theory and related concepts to scales of measurement of clinical disease states and clinical findings (including laboratory data). To gain a more concrete comprehension, we here apply the concept of matrix representation, which was not explicitly exploited in our previous work.

Methods

Starting with a set of orthonormal vectors, called the basis, an operator R_j (an N-tuple patient disease state at the j-th session) was expressed as a set of stratified vectors representing plural operations on individual components, so as to satisfy the group matrix representation.

Results

The stratified vectors containing individual unit operations were combined into one-dimensional square matrices [R_j]s. The [R_j]s meet the matrix representation of a group (ring) as a K-algebra. Using the same-sized matrix of stratified vectors, we can also express changes in the plural set of [R_j]s. The method is demonstrated on simple examples.

Conclusions

Despite the incompleteness of our model, the group matrix representation of stratified vectors offers a formal mathematical approach to clinical medicine, aligning it with other branches of natural science.

     

Investigation on the interaction of letrozole with herring sperm DNA through spectroscopic and modeling methods

The interaction of letrozole, an efficient and safe aromatase inhibitor, with herring sperm DNA (hsDNA) was investigated in vitro through spectroscopy analysis and molecular modeling to elucidate the binding mechanism of anticancer drugs and DNA. The binding constant and the number of binding sites were 2.13 × 10⁴ M^?1 and 1.09, respectively, at 298 K. Thermodynamic parameters (ΔG, ΔH and ΔS) exhibited negative values, which indicated that binding was spontaneous and Van der Waals forces and hydrogen bond were the main interaction forces. Fourier transform infrared spectroscopy and other spectroscopy analysis methods illustrated that letrozole could intercalate into the phosphate backbone of hsDNA and interact with the nitrogenous bases. Consistent with the experimental findings, molecular modeling results demonstrated that the interaction was dominated by intercalation and hydrogen bonding. Copyright © 2015 John Wiley & Sons, Ltd.     

Regulating the Skin Permeation Rate of Escitalopram by Ion-pair Formation with Organic Acids

In order to regulate the skin permeation rate (flux) of escitalopram (ESP), ion-pair strategy was used in our work. Five organic acids with different physicochemical properties, benzoic acid (BA), ibuprofen (IB), salicylic acid (SA), benzenesulfonic acid (BSA), and p-aminobenzoic acid (PABA), were employed as counter-ions to regulate the permeation rate of ESP across the rabbit abdominal skin in vitro. The interaction between ESP and organic acids was characterized by FTIR and ¹³C NMR spectroscopy. Results showed that all organic acids investigated in this study performed a controlling effect on ESP flux. To further analyze the factors concerned with the permeation capability of ESP-acid complex, a multiple linear regression model was used. It is concluded that the steady-state flux (J) of ESP-acid complexes had a positive correlation with log K _o/w (the n-octanol/water partition coefficient of ion-pair complex) and pK _a (the acidity of organic acid counter-ion), but a negative correlation with MW (the molecular weight of ion-pair complex). The logK _o/w of ion-pair complex is the primary one in all the factors that influence the skin permeation rate of ESP. The results demonstrated that organic acid with appropriate physicochemical properties can be considered as suitable candidate for the transdermal drug delivery of escitalopram.     

Highly pathogenic avian influenza H5N1 Clade 2.3.2.1c virus in migratory birds, 2014–2015

A novel Clade 2.3.2.1c H5N1 reassortant virus caused several outbreaks in wild birds in some regions of China from late 2014 to 2015. Based on the genetic and phylogenetic analyses, the viruses possess a stable gene constellation with a Clade 2.3.2.1c HA, a H9N2-derived PB2 gene and the other six genes of Asian H5N1-origin. The Clade 2.3.2.1c H5N1 reassortants displayed a high genetic relationship to a human H5N1 strain (A/Alberta/01/2014). Further analysis showed that similar viruses have been circulating in wild birds in China, Russia, Dubai (Western Asia), Bulgaria and Romania (Europe), as well as domestic poultry in some regions of Africa. The affected areas include the Central Asian, East Asian-Australasian, West Asian-East African, and Black Sea/Mediterranean flyways. These results show that the novel Clade 2.3.2.1c reassortant viruses are circulating worldwide and may have gained a selective advantage in migratory birds, thus posing a serious threat to wild birds and potentially humans.

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Depletion of JMJD5 sensitizes tumor cells to microtubule-destabilizing agents by altering microtubule stability

Microtubules play essential roles in mitosis, cell migration, and intracellular trafficking. Drugs that target microtubules have demonstrated great clinical success in cancer treatment due to their capacity to impair microtubule dynamics in both mitotic and interphase stages. In a previous report, we demonstrated that JMJD5 associated with mitotic spindle and was required for proper mitosis. However, it remains elusive whether JMJD5 could regulate the stability of cytoskeletal microtubules and whether it affects the efficacy of microtubule-targeting agents. In this study, we find that JMJD5 localizes not only to the nucleus, a fraction of it also localizes to the cytoplasm. JMJD5 depletion decreases the acetylation and detyrosination of α-tubulin, both of which are markers of microtubule stability. In addition, microtubules in JMJD5-depleted cells are more sensitive to nocodazole-induced depolymerization, whereas JMJD5 overexpression increases α-tubulin detyrosination and enhances the resistance of microtubules to nocodazole. Mechanistic studies revealed that JMJD5 regulates MAP1B protein levels and that MAP1B overexpression rescued the microtubule destabilization induced by JMJD5 depletion. Furthermore, JMJD5 depletion significantly promoted apoptosis in cancer cells treated with the microtubule-targeting anti-cancer drugs vinblastine or colchicine. Together, these findings suggest that JMJD5 is required to regulate the stability of cytoskeletal microtubules and that JMJD5 depletion increases the susceptibility of cancer cells to microtubule-destabilizing agents.