Inhibition of soluble epoxide hydrolase activity by compounds isolated from the aerial parts of Glycosmis stenocarpa

The aim of this study is to search for soluble epoxide hydrolase (sEH) inhibitors from natural plants, bioassay-guided fractionation of lipophilic n-hexane and chloroform layers of an extract of the aerial parts of Glycosmis stenocarpa led to the isolation of 12 compounds (1–12) including murrayafoline-A (1), isomahanine (2), bisisomahanine (3), saropeptate (4), (24?S)-ergost-4-en-3,6-dione (5), stigmasta-4-en-3,6-dion (6), stigmast-4-en-3-one (7), β-sitosterol (8), 24-methylpollinastanol (9), trans-phytol (10), neosarmentol III (11) and (+)-epiloliolide (12). Their structures were elucidated on the basis of spectroscopic data. Among them, neosarmentol III (11) was isolated from nature for the first time. All the isolated compounds were evaluated for their inhibitory activity against sEH. Among isolated carbazole-type compounds, isomahanine (2) and bisisomahanine (3) were identified as a potent inhibitor of sEH, with IC₅₀ values of 22.5?±?1.7 and 7.7?±?1.2?µM, respectively. Moreover, the inhibitory action of 2 and 3 represented mixed-type enzyme inhibition.     

Temporal and spatial expression of Drosophila Neurexin during the life cycle visualized using a DNRX-Gal4/UAS-reporter

Drosophila neurexin (DNRX) plays a critical role in proper architecture development and synaptic function in vivo. However, the temporal and spatial expression pattern of DNRX still remains unclear. For this study, we generated a novel Drosophila transgenic strain termed the DNRX-Gal4 transgenic line, with characteristic features in agreement with the endogenous DNRX expression pattern. DNRX expression was examined by driving the expression of a GFP reporter (nuclear-localized and membrane- localized GFP) using the DNRX-Gal4 promoter. We found that DNRX was expressed preferentially in central and motor neurons in embryos, larvae and adults, but not in glial cells. DNRX was expressed in pre- and post-synaptic areas in third instar larvae neuromuscular junctions (NMJs). Reporter expression was also observed in the salivary glands, guts, wings and legs of adult flies. In the adult brain, reporter expression was observed throughout several brain regions, including the mushroom body (MBs), antennal lobe (AL) and optic lobe neurons, which is consistent with endogenous DNRX expression via antibody staining. Interestingly, DNRX was also expressed in clock neurons. Meanwhile, we found that DNRX expression in the MBs was required for olfactory learning and memory.     

A euryarchaeal histone modulates strand displacement synthesis by replicative DNA polymerases

Euryarchaeota and Crenarchaeota, the two main lineages of the domain Archaea, encode different chromatin proteins and differ in the use of replicative DNA polymerases. Crenarchaea possess a single family B DNA polymerase (PolB), which is capable of strand displacement modulated by the chromatin proteins Cren7 and Sul7d. Euryarchaea have two distinct replicative DNA polymerases, PolB and PolD, a family D DNA polymerase. Here we characterized the strand displacement activities of PolB and PolD from the hyperthermophilic euryarchaeon Pyrococcus furiosus and investigated the influence of HPfA1, a homolog of eukaryotic histones from P. furiosus, on these activities. We showed that both PolB and PolD were efficient in strand displacement. HPfA1 inhibited DNA strand displacement by both DNA polymerases but exhibited little effect on the displacement of a RNA strand annealed to single-stranded template DNA. This is consistent with the finding that HPfA1 bound more tightly to double-stranded DNA than to a RNA:DNA hybrid. Our results suggest that, although crenarchaea and euryarchaea differ in chromosomal packaging, they share similar mechanisms in modulating strand displacement by DNA polymerases during lagging strand DNA synthesis.     

Increased plant growth and copper uptake of host and non-host plants by metal-resistant and plant growth-promoting endophytic bacteria

The effects of inoculation with two metal-resistant and plant growth-promoting endophytic bacteria (Burkholderia sp. GL12 and Bacillus megaterium JL35) were evaluated on the plant growth and Cu uptake in their host Elsholtzia splendens and non-host Brassica napus plants grown in natural Cu-contaminated soil. The two strains showed a high level of ACC deaminase activities. In pot experiments, inoculation with strain GL12 significantly increased root and above-ground tissue dry weights of both plants, consequently increasing the total Cu uptake of E. splendens and Brassica napus by 132% and 48.2% respectively. Inoculation with strain JL35 was found to significantly increase not only the biomass of B. napus, consequently increasing the total Cu uptake of B. napus by 31.3%, but Cu concentration of E. splendens for above-ground tissues by 318% and roots by 69.7%, consequently increasing the total Cu uptake of E. splendens by 223%. The two strains could colonize the rhizosphere soils and root interiors of both plants. Notably, strain JL35 could colonize the shoot tissues and significantly increase the translocation factors and bioaccumulation factors of E. splendens. These results suggested that Burkholderia sp. GL12 and B. megaterium JL35 were valuable bacterial resource which had the potential in improving the efficiency of Cu phytoextraction by E. splendens and B. napus in a natural Cu-contaminated soil.     

Study of the binding and energy transfer of erbium ion with rhaponticin and its pharmacokinetics application

Binding and energy transfer of an erbium ion with rhaponticin (RH) was investigated and a simple spectrofluorimetric method was developed for determination of RH using an Er³⁺ probe. Results using spectra, chromatography and density functional theory (DFT) indicated that binding of Er³⁺ to RH occurred at the hydroxyl group of C‐11 and at the methoxy group at C‐12 of the conjugated aromatic ring through hydrogen bonding. Resonance energy transfer (RET) occurred from intramolecular charge transfers (ICT), the binding of RH to Er³⁺ ion induced fluorescence enhancement (FE) of the Er³⁺ ion. This method was applied to the pharmacokinetic detection of RH. The main advantages of the proposed method compared with previously reported ones are its simplicity and lower cost. Copyright © 2016 John Wiley & Sons, Ltd.     

Amino acids essential for the interaction between cellular heat shock protein 90 and a Kaposi’s sarcoma-associated herpesvirus-encoded protein kinase ORF36

Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s12250-016-3839-9 and is accessible for authorized users.     

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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Overexpression of cyclin D1 induces the reprogramming of differentiated epidermal cells into stem cell-like cells

It has been reported that Wnt/β-catenin is critical for dedifferentiation of differentiated epidermal cells. Cyclin D1 (CCND1) is a β-catenin target gene. In this study, we provide evidence that overexpression of CCND1 induces reprogramming of epidermal cells into stem cell-like cells. After introducing CCND1 gene into differentiated epidermal cells, we found that the large flat-shaped cells with a small nuclear-cytoplasmic ratio changed into small round-shaped cells with a large nuclear-cytoplasmic ratio. The expressions of CK10, β1-integrin, Oct4 and Nanog in CCND1 induced cells were remarkably higher than those in the control group (P < 0.01). In addition, the induced cells exhibited a high colony-forming ability and a long-term proliferative potential. When the induced cells were implanted into a wound of laboratory animal model, the wound healing was accelerated. These results suggested that overexpression of CCND1 induced the reprogramming of differentiated epidermal cells into stem cell-like cells. This study may also offer a new approach to yield epidermal stem cells for wound repair and regeneration.