Understanding super-enhancers

正Super-enhancers are defined as cluster of enhancers with dense TF binding,which can activate proximal cell-identity gene expression.Here we review the identification,functional significance of super-enhancers,and their relationships with cancer.With the current intense interests in super-enhancers,more super-enhancers will be defined and     

有色大麦种质芽期耐盐性鉴定

以44份有色大麦种质为试材,通过测定发芽势、发芽率、发芽指数、萌发活力指数结合两个颜色指标YU(颜色亮度和浓度)进行芽期的耐盐性鉴定,并运用相关性分析、主成分分析、聚类分析等方法对有色大麦材料进行多指标耐盐性综合评价。结果表明,发芽率和发芽指数对盐胁迫响应最为敏感,芽长和根长对盐胁迫响应较为迟钝;粒色亮度与耐盐性综合评价F值呈显著负相关;粒色浓度与耐盐性综合评价F值呈显著正相关;综合指标F值相关分析表明,颜色越深,耐盐性越强;用综合指标F值,可将44份有色大麦分为4类,其中强耐盐材料包括XZDM-1401、XZDM-1404、XZDM-1543、XZDM-1546等4份,中等耐盐性包括XZDM-926、XZDM-957、XZDM-972等16份,弱耐盐性包括XZDM-815、XZDM-1606、XZDM-1030等12份,敏盐性包括XZDM-973、XZDM-1042、XZDM-1318等12份。     

Lithium Dendrites Inhibition via Diffusion Enhancement

The dendritic structure is a disastrous problem of lithium metal batteries as well as other metal rechargeable batteries. The dendritic structures are usually caused by diffusion limitation. Here, a novel strategy is reported to inhibit lithium dendrites based on the understanding of their formation mechanism. An alternating current field perpendicular to the anode is set up, which promotes Li⁺ movement along the anode surface and prevents ions' deposition on the tips from forming dendrites. Furthermore, an external direct current field parallel to the current is employed, which accelerates the transport of Li⁺ in electrolytes to mitigate the concentration gradient nearby the anode and thus inhibits the formation of dendritic structures. A simultaneous employment of these two fields gains five times increase of the lifespan of batteries at the high charging current density of 2 mA cm^?2, confirming the effectiveness of this strategy in protecting the metal anode and inhibiting lithium dendrites. This strategy may have a wide feasibility since it does not change the materials and structures of batteries.     

Identification of new dual FABP4/5 inhibitors based on a naphthalene-1-sulfonamide FABP4 inhibitor

Fatty acid binding protein 4 (FABP4) and fatty acid binding protein 5 (FABP5) are mainly expressed in adipocytes and/or macrophages and play essential roles in energy metabolism and inflammation. When FABP4 function is diminished, FABP5 expression is highly increased possibly as a functional compensation. Dual FABP4/5 inhibitors are expected to provide beneficial synergistic effect on treating diabetes, atherosclerosis, and inflammation-related diseases. Starting from our previously reported selective FABP4 inhibitor 8, structural biology information was used to modulate the selectivity profile and to design potent dual FABP4/5 inhibitors with good selectivity against FABP3. Two compounds A16 and B8 were identified to show inhibitory activities against both FABP4/5 and good selectivity over FABP3, which could also reduce the level of forskolin-stimulated lipolysis in mature 3T3-L1 adipocytes. Compared with compound 8, these two compounds exhibited better anti-inflammatory effects in lipopolysaccharide-stimulated RAW264.7 murine macrophages, with decreased levels of pro-inflammatory cytokines TNFα and MCP-1 and apparently inhibited IKK/NF-κB pathway.     

Development of high‐resolution DNA barcodes for Dioscorea species discrimination and phylogenetic analysis

The genus Dioscorea is widely distributed in tropical and subtropical regions, and is economically important in terms of food supply and pharmaceutical applications. However, DNA barcodes are relatively unsuccessful in discriminating between Dioscorea species, with the highest discrimination rate (23.26%) derived from matK sequences. In this study, we compared genic and intergenic regions of three Dioscorea chloroplast genomes and found that the density of SNPs and indels in intergenic sites was about twice and seven times higher than that of SNPs and indels in the genic regions, respectively. A total of 52 primer pairs covering highly variable regions were designed and seven pairs of primers had 80%–100% PCR success rate. PCR amplicons of 73 Dioscorea individuals and assembled sequences of 47 Dioscorea SRAs were used for estimating intraspecific and interspecific divergence for the seven loci: The rpoB‐trnC locus had the highest interspecific divergence. Automatic barcoding gap discovery (ABGD), Poisson tree processes (PTP), and generalized mixed Yule coalescence (GMYC) analysis were applied for species delimitation based on the seven loci and successfully identified the majority of species, except for species in the Enantiophyllum section. Phylogenetic analysis of 51 Dioscorea individuals (28 species) showed that most individuals belonging to the same species tended to cluster in the same group. Our results suggest that the variable loci derived from comparative analysis of plastid genome sequences could be good DNA barcode candidates for taxonomic analysis and species delimitation.     

High performance liquid chromatographic determination of 1,2-[bis(1,2-benzisoselenazolone-3(2H)-ketone)]-ethane (BBSKE), a novel organoselenium compound, in dog plasma using pre-column derivatization and its application in pharmacokinetic study

A novel HPLC-UV method with pre-column derivatization by using 2-mercaptoethanol was established for determination of 1,2-[bis(1,2-benzisoselenazolone-3(2H)-ketone)]-ethane (BBSKE) in dog plasma. The derivatives were identified by mass spectrometry. The method had a good linear range of 0.05-2 microg/ml (r(2)=0.9995). The lower limit of quantification (LOQ) was 0.05 microg/ml. The precision and accuracy were less than 7%. After dosing of BBSKE (30 mg/kg, p.o. and 0.79 mg/kg, i.v.) in dogs, AUC(0-t) were 5.72+/-2.42 and 1.35+/-0.41 microg h/ml; t(1/2) were 4.6+/-2.1 and 1.7+/-0.6h, respectively. The method was successfully applied to the pharmacokinetic study in dogs.     

矮化香蕉及其野生型GA3ox基因的结构特点和表达分析

香蕉的矮化突变是香蕉无性繁殖后代最常见的表型变异之一,但其变异的分子调控机理目前尚未研究清楚; 而内源赤霉素是影响植物株高的重要激素之一,GA3-氧化酶是赤霉素生物合成后期的关键酶。为探究GA3-氧化酶编码基因对香蕉矮化的分子调控机理,该研究以威廉斯B6矮化突变体及其野生型亲本为材料,通过RT-PCR技术克隆得到矮化香蕉及其野生型亲本GA3ox基因的全长cDNA序列,并对其推测的氨基酸序列进行比对分析,同时利用qRT-PCR技术对GA3ox基因在不同组织中的表达水平差异进行分析。结果表明:(1)矮化香蕉GA3ox-A和野生型香蕉GA3ox-G的ORF长度均为864 bp,均编码287个氨基酸,经序列比对分析发现两条氨基酸序列之间存在5个位点的差异,从而产生具有不同性质的蛋白质。(2)氨基酸序列同源性分析表明,矮化香蕉GA3ox的氨基酸序列与油棕、海枣、椰子的同源性最高。(3)qRT-PCR显示,GA3ox基因在矮化香蕉叶片和茎秆中的表达水平整体上低于野生型,其中GA3ox在野生型茎秆中的表达水平是矮化植株的2.2～32倍。综上推测,GA3ox基因可能对香蕉茎杆的矮化变异具有重要的调控作用。该研究结果为揭示香蕉矮化突变的分子机制与筛选优良矮化香蕉株系奠定了基础。     

NAMPT regulates PKM2 nuclear location through 14-3-3ζ: Conferring resistance to tamoxifen in breast cancer

The resistance against tamoxifen therapy has become one of the major obstacles in the clinical treatment of breast cancer. Nicotinamide phosphoribosyltransferase (NAMPT) is an essential enzyme catalyzing nicotinamide adenine dinucleotide biosynthesis and is important for tumor metabolism. The study here sought to explore the effect of NAMPT on breast cancer survival with tamoxifen conditioning. We found that NAMPT was highly expressed in breast cancer cells compared with normal mammary epithelial cells. Inhibition of NAMPT by FK866 inhibited cell viability and aggravated apoptosis in cancer cells treated with 4-hydroxytamoxifen. NAMPT overexpression upregulated 14-3-3ζ expression. Knockdown of 14-3-3ζ reduced cell survival and promoted apoptosis. Activation of Akt signaling, rather than ERK1/2 pathway, is responsible for 14-3-3ζ regulation by NAMPT overexpression. Furthermore, NAMPT overexpression led to PKM2 accumulation in the cell nucleus and could be dampened by 14-3-3ζ inhibition. In addition, NAMPT overexpression promoted xenografted tumor growth and apoptosis in nude mice, while 14-3-3ζ inhibition attenuated its effect. Collectively, our data demonstrate that NAMPT contributes to tamoxifen resistance through regulation of 14-3-3ζ expression and PKM2 translocation.     

Estimation of above-ground biomass of reed (Phragmites communis) based on in situ hyperspectral data in Beijing Hanshiqiao Wetland,China

Wetlands Ecology and Management - Accurate estimates of reed (Phragmites communis) biomass are critical for efficient reed swamp monitoring and management. This study compared the accuracy of...