RNF7 promotes glioma growth via the PI3K/AKT signalling axis

RNF7 has been reported to play critical roles in various cancers. However, the underlying mechanisms of RNF7 in glioma development remain largely unknown. Herein, the expression level of RNF7 was examined in tissues by quantitative real-time PCR, Western blotting and immunohistochemistry. The effect of RNF7 on glioma progression was measured by performing CCK-8 and apoptosis assays, cell cycle-related experiments and animal experiments. The effect of RNF7 on PI3K/AKT signalling pathway was tested by Western blotting. First, we found that RNF7 was upregulated in tumour tissue compared with normal brain tissue, especially in high-grade glioma, and the high expression of RNF7 was significantly related to tumour size, Karnofsky Performance Scale score and a poor prognosis. Second, RNF7 overexpression facilitated tumour cell cycle progression and cell proliferation and suppressed apoptosis. Conversely, RNF7 knockdown suppressed tumour cell cycle progression and cell proliferation and facilitated apoptosis. Furthermore, follow-up mechanistic studies indicated that RNF7 could facilitate glioma cell proliferation and cell cycle progression and inhibit apoptosis by activating the PI3K/AKT signalling pathway. This study shows that RNF7 can clearly promote glioma cell proliferation by facilitating cell cycle progression and inhibiting apoptosis by activating the PI3K/AKT signalling pathway. Targeting the RNF7/PI3K/AKT axis may provide a new perspective on the prevention or treatment of glioma.     

Enzyme-linked immunosorbent assays for detection and quantitation of the entomocidal parasporal crystalline protein of Bacillus thuringiensis subspp. kurstaki and israelensis.

An enzyme-linked immunosorbent assay was used to detect and quantitate the parasporal crystal toxins of Bacillus thuringiensis subspp. kurstaki and israelensis. The assay method described is extremely sensitive, accurate, and highly specific. With this technique, crystalline insecticidal proteins from several subspecies of B. thuringiensis were compared. The dipteran crystal toxin produced by B. thuringiensis subsp. israelensis was shown to share few epitopes with the lepidopteran toxin from B. thuringiensis subspp. kurstaki, tolworthi, berliner, and alesti.     

番木瓜环斑病毒复制酶(亚基)基因的克隆、序列分析及其植物表达载体的构建

近二年报道,在TMV^⑴、PVX^⑵、PEBV^⑶和CMV^⑷等病毒中,利用病毒编码的复制酶(亚基)基因或相关cDNA片段转化烟草,工程植株获得绝对或极高的病毒抗性。大量研究认为：马铃薯Y病毒组的核内含体大分子量蛋白(Nib)是依赖于RNA的RNA复制酶(或核心亚基),Nlb与上述病毒的复制酶有广泛的同源保守区^⑸。因此,Nib基因的克隆,不但在植物抗病基因工程方面,而且在马铃薯Y病毒组基因组的复制研究方面．均有重要的意义。本文以马铃薯Y病毒组的重要成员番木瓜环斑病毒的华南强株系(PRSV—sM)为材料,克隆了PRSV的Nib基因,并完成其全序列测定和植物表达载体的构建,为探索马铃薯Y病毒组复制酶可能介导的抗病性打下了基础。     

脂环酸芽孢杆菌D-1的耐盐内切葡聚糖酶基因克隆、表达与酶学性质北大核心CSCD

【目的】克隆温泉中嗜热嗜酸的脂环酸芽孢杆菌D-1(Alicyclobacillus tengchongensis CGMCC1504)的内切葡聚糖酶基因gluE1,并对该酶进行序列分析和重组酶的酶学特性分析。【方法】通过全基因组测序获得gluE1全长,并对其氨基酸序列(GluE1)进行分析。将gluE1重组到载体p EASY-E2中并转化到大肠杆菌BL21(DE3)中异源表达,利用组氨酸标签纯化GluE1并进行酶学性质分析。【结果】gluE1与NCBI数据库中GH5的内切葡聚糖酶具有较高的相似性,全长1020 bp,GC含量50.5%,编码339个氨基酸(40.45 k Da)。GluE1与数据库中序列的最高一致性为97%,与其余纤维素酶的一致性<60%。GluE1可水解CMC-Na、可溶性淀粉和大麦β-葡聚糖,表观最适pH为6.5,pH 5.0–10.0稳定并维持60%以上的酶活性。GluE1的表观最适温度为55℃,在37℃下稳定。在55℃ pH 6.5条件下,GluE1对大麦β-葡聚糖的K_m、V_(max)和k_(cat)分别为8.58 mg/mL、416.67 U/mg和280.90 s^(–1)。GluE1受Ag^+、Hg^(2+)及SDS抑制,β-巯基乙醇、Pb^(2+)、Mg^(2+)、Ca^(2+)和Na^+对GluE1有微弱的促进作用,NaCl对GluE1的影响不大,加入30%的NaCl,仍有64%以上的酶活性;经30%的NaCl在37℃下处理60 min,仍能保持93%以上的活性。【结论】首次报道从Alicyclobacillus属的细菌中克隆得到内切葡聚糖酶基因并对其酶学性质进行研究,GluE1具有良好的pH稳定性和有较强的耐盐性,可能具有更大应用潜力。     

Development of Simple Sequence Repeat Markers from De Novo Assembled Transcriptomes of Pumpkins

Plant Molecular Biology Reporter - Pumpkin (Cucurbita spp.) is one of the major vegetable crops grown worldwide. The number of simple sequence repeat (SSR) markers in pumpkins lags far behind the...     

Involvement of putrescine and nitric oxide in aluminum tolerance by modulating citrate secretion from roots of red kidney bean

Background and Aims

Polyamines and nitric oxide (NO) are two important molecules modulating numerous environment stresses in plants. This study was to investigate the roles of polyamines and NO in aluminum (Al) tolerance in red kidney bean.

Methods

The interaction between putrescine (Put) and NO under Al stress was examined. NO donor and scavenger were used to further examine the role of NO in Al-induced citrate secretion from roots by high performance liquid chromatography.

Results

Al stress caused increase of endogenous free Put, and exogenous Put alleviated Al-induced inhibition of root elongation and Al accumulation. In addition, Put induced NO production and nitrate reductase (NR) activity under Al stress. Al- and Put-induced NO production could be reversed by NR inhibitor. Furthermore, Al stress stimulated citrate secretion from roots, and this response was stimulated by NO donor, whereas NO scavenger inhibited Al-induced citrate secretion from roots. Concomitantly, NO donor reduced Al accumulation in root apexes, while NO scavenger further enhanced Al accumulation. Al-induced inhibition of root growth was significantly improved by exogenous citrate treatment.

Conclusions

Put and NO enhanced Al tolerance by modulating citrate secretion from roots, and NO may act downstream of Put in red kidney bean under Al stress.     

Difference analysis of the enzymatic hydrolysis performance of acid-catalyzed steam-exploded corn stover before and after washing with water

The difference in the enzymatic hydrolysis yield of acid-catalyzed steam-exploded corn stover (ASC) before and after washing with water reached approximately 15 % under the same conditions. The reasons for the difference in the yield between ASC and washed ASC (wASC) were determined through the analysis of the composition of ASC prehydrolyzate and sugar concentration of enzymatic hydrolyzate. Salts produced by neutralization (CaSO₄, Na₂SO₄, K₂SO₄, and (NH₄)₂SO₄), sugars (polysaccharides, oligosaccharides, and monosaccharides), sugar-degradation products (weak acids and furans), and lignin-degradation products (ethyl acetate extracts and nine main lignin-degradation products) were back-added to wASC. Results showed that these products, except furans, exerted negative effect on enzymatic hydrolysis. According to the characteristics of acid-catalyzed steam explosion pretreatment, the five sugar-degradation products’ mixture and salts [Na₂SO₄, (NH₄)₂SO₄] showed minimal negative inhibition effect on enzymatic hydrolysis. By contrast, furans demonstrated a promotion effect. Moreover, soluble sugars, such as 13 g/L xylose (decreased by 6.38 %), 5 g/L cellobiose (5.36 %), 10 g/L glucose (3.67 %), as well as lignin-degradation products, and ethyl acetate extracts (4.87 %), exhibited evident inhibition effect on enzymatic hydrolysis. Therefore, removal of soluble sugars and lignin-degradation products could effectively promote the enzymatic hydrolysis performance.     

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.     

Engineering the stem cell microenvironment

Multipotent stem cells in the body facilitate tissue regeneration, growth, and wound healing throughout life. The microenvironment in which they reside provides signals that direct these progenitors to proliferate, differentiate, or remain dormant; these factors include soluble molecules, the extracellular matrix, neighboring cells, and physical stimuli. Recent advances in the culture of embryonic stem cells and adult progenitors necessitate an increased understanding of these phenomena. Here, we summarize the interactions between stem cells and their local environment, drawing on in vivo observations and tissue culture studies. In addition, we describe novel methods of characterizing the effects of various environmental factors and review new techniques that enable scientists and engineers to more effectively direct stem cell fate.