Variable Nornicotine Enantiomeric Composition Caused by Nicotine Demethylase CYP82E4 in Tobacco Leaf

Nornicotine is the demethylation product of nicotine and the precursor of tobacco-specific nitrosamine <i>N′</i>-nitrosonornicotine (NNN) in tobacco (<i>Nicotiana tabacum</i> L.). There is an inconsistent enantiomer fraction (EF) of nornicotine reported in the literature. The objective of this study was to explore possible mechanisms to account for the variable EF_nnic in tobacco. A survey of tobacco with different demethylating capabilities confirmed that there was variable EF_nnic. Experiments of induction and inhibition of the major nicotine demethylase CYP82E4 activity in tobacco demonstrated that CYP82E4 selectively demethylated (<i>S</i>)-nicotine and resulted in different EF_nnic in tobacco leaves. Results from plants with silenced demethylases by RNAi suggested that other demethylases selectively used (<i>R</i>)-nicotine and resulted in high EF_nnic. In summary, enantioselective demethylation likely plays an important role in contributing to a large and variable EF_nnic observed in tobacco

<i>Populus</i> transcription factors in Module 4.

<p><i>Populus</i> transcription factors in Module 4.</p

Systematic Identification of Cell-Wall Related Genes in <i>Populus</i> Based on Analysis of Functional Modules in Co-Expression Network

<div><p>The identification of novel genes relevant to plant cell wall (PCW) biosynthesis in <i>Populus</i> is a highly important and challenging problem. We surveyed candidate <i>Populus</i> cell wall genes using a non-targeted approach. First, a genome-wide <i>Populus</i> gene co-expression network (PGCN) was constructed using microarray data available in the public domain. Module detection was then performed, followed by gene ontology (GO) enrichment analysis, to assign the functional category to these modules. Based on GO annotation, the modules involved in PCW biosynthesis were then selected and analyzed in detail to annotate the candidate PCW genes in these modules, including gene annotation, expression of genes in different tissues, and so on. We examined the overrepresented cis-regulatory elements (CREs) in the gene promoters to understand the possible transcriptionally co-regulated relationships among the genes within the functional modules of cell wall biosynthesis. PGCN contains 6,854 nodes (genes) with 324,238 edges. The topological properties of the network indicate scale-free and modular behavior. A total of 435 modules were identified; among which, 67 modules were identified by overrepresented GO terms. Six modules involved in cell wall biosynthesis were identified. Module 9 was mainly involved in cellular polysaccharide metabolic process in the primary cell wall, whereas Module 4 comprises genes involved in secondary cell wall biogenesis. In addition, we predicted and analyzed 10 putative CREs in the promoters of the genes in Module 4 and Module 9. The non-targeted approach of gene network analysis and the data presented here can help further identify and characterize cell wall related genes in <i>Populus</i>.</p></div

Convergent Synthesis of Novel Muramyl Dipeptide Analogues: Inhibition of Porphyromonas gingivalis-Induced Pro-inflammatory Effects by High Doses of Muramyl Dipeptide

Porphyromonas gingivalis (<i>P.g.</i>)-induced TNF-α can be affected by muramyl dipeptide (MDP) in a biphasic concentration-dependent manner. We found that in <i>P.g.</i>-exposed macrophages, treatment with 10 μg/mL of MDP (MDP-low) up-regulated TNF-α by 29%, while 100 μg/mL or higher (MDP-high) significantly decreased it (16% to 38%). MDP-high was found to affect the ubiquitin-editing enzyme A20 and activator protein 1 (AP1). An AP1 binding site was found in the promoter region of A20. A20 promoter activity was up-regulated after transfection of AP1 cDNA in cells. Four analogues of MDP (<b>3</b>–<b>6</b>) were prepared through a convergent strategy involving the synthesis of two unique carbohydrate fragments, <b>7a</b> and <b>7b</b>, using the peptide coupling reagents, EDCI and HOAt. Analogue <b>4</b> improved MDP function and <i>P.g.</i>-induced activities. We propose a new signaling pathway for TNF-α induction activated after exposing macrophages to both <i>P.g.</i> and MDP-high or analogue <b>4</b>

Co-expression relationship between transcription factors (TFs) in Module 4 of PGCN.

<p>A node represents a TF gene and an edge indicates a significant co-expression relationship between two genes. The gene name of the <i>Arabidopsis</i> homologous gene is used for each TF.</p

Overrepresented cis-regulatory elements in Module 4 and Module 9 of PGCN.

<p>Overrepresented cis-regulatory elements in Module 4 and Module 9 of PGCN.</p

A flowchart of the computational analysis pipeline for discovery of plant cell wall genes.

<p>A flowchart of the computational analysis pipeline for discovery of plant cell wall genes.</p

DataSheet1_Yangjing capsule improves oligoasthenozoospermia by promoting nitric oxide production through PLCγ1/AKT/eNOS pathway.docx

Background: Oligoasthenozoospermia is an important factor leading to male infertility. Yangjing capsule (YC), a traditional Chinese preparation, displays beneficial effects on male infertility. However, whether YC could improve oligoasthenozoospermia remains unclear.Methods: In this study, we aimed to explore the effect of YC in the treatment of oligoasthenozoospermia. Male Sprague-Dawley (SD) rats were treated with 800 mg/kg ornidazole once daily for 30 days to induce in vivo oligoasthenozoospermia; primary Sertoli cells were treated with 400 μg/mL ornidazole for 24 h to induce in vitro oligoasthenozoospermia.Results: We found that YC improved the testicle and epididymis weight, sperm concentration, sperm progressive motility, serum testosterone, fertility rate and testis morphology in ornidazole-exposed rats and enhanced cell survival in ornidazole-stimulated primary Sertoli cells. YC also inhibited the ornidazole-caused decrease in nitric oxide (NO) generation and the phosphorylation of phospholipase C γ1 (PLCγ1), AKT, and eNOS in vivo and in vitro in oligoasthenozoospermia. Furthermore, the knockdown of PLCγ1 blunted the beneficial effects of YC in vitro.Conclusion: Collectively, our data suggested that YC protected against oligoasthenozoospermia by promoting NO levels through the PLCγ1/AKT/eNOS pathway.</p

The single-photon transmission spectrum under the symmetrical atom–photon couplings (<em>g</em>₁ = <em>g</em>₂ = 0.2)

<p><strong>Figure 2.</strong> The single-photon transmission spectrum under the symmetrical atom–photon couplings (<em>g</em>₁ = <em>g</em>₂ = 0.2). 2θ = 2π for the red line, 2θ = π for the blue line, and 2θ = 0.4π for the green line. The coupling strengths <em>g</em>₁ and <em>g</em>₂ are in units of <em>V</em>_g.</p> <p><strong>Abstract</strong></p> <p>Based on the symmetric, asymmetric atom–photon couplings and the phase difference between two separated atoms, single-photon transport properties in an optical waveguide coupled with two separated two-level atoms are theoretically investigated. The transmission and reflection amplitudes for the single-photon propagation in such a hybrid system are deduced via a real-space approach. Several new phenomena such as phase-coupled induced transparency, single-photon switches, symmetric and asymmetric bifrequency photon attenuators are analyzed. In addition, the dissipation effect of such a hybrid system is also discussed.</p

The single-photon transmission spectrum under symmetrical atom–photon couplings and 2θ = 2π (a), 2θ = π (b), 2θ = 0.4π (c) with Ω₁ = 0.9 Ω (left atom) and Ω₂ = 1.1 Ω (right atom) and Ω = 1.0

<p><strong>Figure 4.</strong> The single-photon transmission spectrum under symmetrical atom–photon couplings and 2θ = 2π (a), 2θ = π (b), 2θ = 0.4π (c) with Ω₁ = 0.9 Ω (left atom) and Ω₂ = 1.1 Ω (right atom) and Ω = 1.0. (d) The energy-level configuration of the Λ-type three-level atom. <em>V</em>₁ = <em>g</em>₁²/2 <em>v_g</em> = 0.2 and <em>V</em>₂ = <em>g</em>₂²/2 <em>v_g</em>. The coupling strengths <em>g</em>₁ and <em>g</em>₂ are in units of <em>V</em>_g.</p> <p><strong>Abstract</strong></p> <p>Based on the symmetric, asymmetric atom–photon couplings and the phase difference between two separated atoms, single-photon transport properties in an optical waveguide coupled with two separated two-level atoms are theoretically investigated. The transmission and reflection amplitudes for the single-photon propagation in such a hybrid system are deduced via a real-space approach. Several new phenomena such as phase-coupled induced transparency, single-photon switches, symmetric and asymmetric bifrequency photon attenuators are analyzed. In addition, the dissipation effect of such a hybrid system is also discussed.</p