Exploring the expression bar code of SAA variants for gastric cancer detection

We reported an integrated platform to explore serum protein variant pattern in cancer and its utility as a new class of biomarker panel for diagnosis. On the model study of serum amyloid A (SAA), we employed nanoprobe‐based affinity mass spectrometry for enrichment, identification and quantitation of SAA variants from serum of 105 gastric cancer patients in comparison with 54 gastritis patients, 54 controls, and 120 patients from other cancer. The result revealed surprisingly heterogeneous and most comprehensive SAA bar code to date, which comprises 24 SAA variants including SAA1‐ and SAA2‐encoded products, polymorphic isoforms, N‐terminal–truncated forms, and three novel SAA oxidized isotypes, in which the variant‐specific peptide sequence were also confirmed by LC‐MS/MS. A diagnostic model was developed for dimension reduction and computational classification of the 24 SAA‐variant bar code, providing good discrimination (AUC = 0.85 ± 3.2E?3) for differentiating gastric cancer group from gastritis and normal groups (sensitivity, 0.76; specificity, 0.81) and was validated with external validation cohort (sensitivity, 0.71; specificity, 0.74). Our platform not only shed light on the occurrence and modification extent of under‐represented serum protein variants in cancer, but also suggested a new concept of diagnostic platform by serum protein variant profile.     

Long noncoding RNA ATB promotes ovarian cancer tumorigenesis by mediating histone H3 lysine 27 trimethylation through binding to EZH2

Ovarian cancer (OC) remains one of the most lethal gynecological malignancies. The unfavourable prognosis is mainly due to the lack of early-stage diagnosis, drug resistance and recurrence. Therefore, it needs to investigate the mechanism of OC tumorigenesis and identify effective biomarkers for the clinical diagnosis. It is reported that long noncoding RNAs (lncRNAs) play important roles during the tumorigenesis of OC. Therefore, the present study aimed to study the role and clinical significance of LncRNAs ATB (lnc-ATB) in the development and progression of OC. In our research, lnc-ATB expression in OC tissues was elevated compared with adjacent normal tissues and high expression of lnc-ATB was associated with poor outcomes of OC patients. The silencing of lnc-ATB blocked cell proliferation, invasion and migration in SKOV3 and A2780 cells. RNA immunoprecipitation and RNA pull-down results showed that lnc-ATB positively regulated the expression of EZH2 via directly interacting with EZH2. Besides, the overexpression of EZH2 partly rescued lnc-ATB silencing-inducing inhibition of cell proliferation, invasion and migration. Chromatin immunoprecipitation assay results demonstrated that the silencing of lnc-ATB reduced the occupancy of caudal-related homeobox protein 1, Forkhead box C1, Large tumour suppressor kinase 2, cadherin-1 and disabled homolog 2 interacting protein promoters on EZH2 and H3K27me3. These data revealed the oncogenic of lnc-ATB and provided a novel biomarker for OC diagnosis. Furthermore, these findings indicated the mechanism of lnc-ATB functioning in the progression of OC, which provided a new target for OC therapy.     

Toxicity of A Novel Neonicotinoid Insecticide Paichongding to Earthworm Eisenia fetida

Traditional neonicotinoid insecticides are used worldwide. Paichongding (IPP), as a novel neonicotinoid pesticide, has been widely used in China. However, the ecotoxicity of IPP to non-target invertebrates in soil ecosystem has not been reported yet. In this study, acute toxicity of IPP to earthworm Eisenia fetida, as well as the antioxidant response after IPP exposure, was evaluated. In the filter paper contact test, the LC₅₀ at 24 hr and 48 hr for IPP were 14.98 μg/cm² and 7.59 μg/cm², respectively. In artificial soil test, the LC₅₀ (lethal concentration) at 14 days and 28 days for IPP were 541.07 mg/kg and 238.51 mg/kg, respectively. The LC₅₀ of IPP is much higher than that of traditional neonicotinoid insecticides. However, earthworm body weight assessment demonstrated that the growth of earthworm was inhibited by extended exposure to IPP at sublethal doses. The activities of antioxidative enzymes superoxide dismutase and catalase in earthworms were significantly induced after IPP exposure. Malondialdehyde, a biomarker of lipid peroxidation, was also increased after IPP exposure. Although the results indicated that IPP had potentially adverse effect on earthworms, its toxicity was much lower than traditional neonicotinoids.     

Genetic regulation by non-coding RNAs

Large scale cDNA sequencing and genome tiling array studies have shown that around 50% of genomic DNA in humans is transcribed, of which 2% is translated into proteins and the remaining 98% is non-coding RNAs (ncRNAs). There is mounting evidence that these ncRNAs play critical roles in regulating DNA structure, RNA expression, protein translation and protein functions through multiple genetic mechanisms, and thus affect normal development of organisms at all levels. Today, we know very little about the regulatory mechanisms and functions of these ncRNAs, which is clearly essential knowledge for understanding the secret of life. To promote this emerging research subject of critical importance, in this paper we review (1) ncRNAs' past and present, (2) regulatory mechanisms and their functions, (3) experimental strategies for identifying novel ncRNAs, (4) experimental strategies for investigating their functions, and (5) methodologies and examples of the application of ncRNAs.     

Demecolcine-induced enucleation of sheep meiotically maturing oocytes

The objective of this study was to investigate the possible effect of demecolcine, a microtubule-disrupting reagent, on induced enucleation (IE) of sheep meiotically maturing oocytes. Immunofluorescent staining with anti-tubulin antibodies was used to examine the spindle status of the oocytes. When the oocytes with intact germinal vesicles (GV) were cultured in the medium containing various concentrations of demecolcine (0.01 to 0.4 microg.mL-1) for 20 to 22 h, the spindle microtubule organization and first polar body (PB1) extrusion were inhibited by demecolcine in a dose-dependent manner. The highest IE rate (58.1%) was from the treatment with 0.04 microg.mL-1 demecolcine. Demecolcine treatment applied after germinal vesicle breakdown (GVBD) or at metaphase (M) yielded a PB1 extrusion rate and IE efficiency similar to the treatment applied at the onset of maturation. Analysis by immunofluorescence showed that both nonspindle microtubules and spindle microtubules were significantly disorganized by demecolcine. Combination treatment with demecolcine and cycloheximide (CHX) or 6-dimethylaminopurine (6-DMAP) led to single pronuclear formation rather than PB1 extrusion. When demecolcine-treated oocytes were transferred into demecolcine-free medium, the ability to extrude PB1 was quickly restored and a 72.1% IE rate was obtained following such treatment. These results demonstrate that demecolcine can be used as a potential reagent for induced enucleation of sheep meiotically maturing oocytes and may greatly facilitate research in nuclear transfer.     

Climate warming and atmospheric deposition affect seed viability of common juniper (<Emphasis Type="Italic">Juniperus communis</Emphasis>) via their impact on the nutrient status of the plant

Global environmental change is increasingly affecting species worldwide. One of the emblematic casualties among plants in several European countries is common juniper (Juniperus communis). Many populations of common juniper throughout its distribution range are declining. The relative lack of viable seed production, resulting in low probabilities for successful natural regeneration, is one of the main reasons for this decline. Climate warming and elevated atmospheric depositions have been shown to negatively affect seed viability of common juniper, but our understanding of the underlying mechanisms remains scarce. One possible pathway is via changes in the plant nutrient status that, in turn, may affect seed viability. Here we took advantage of large-scale gradients in climate and atmospheric depositions between central Sweden and northern Spain, and analysed foliar nutrient concentrations and stoichiometry and seed viability in 20 juniper populations spread across Europe. Our results show that increasing temperatures can negatively affect needle N and P concentrations while enhanced potentially acidifying depositions resulted in lower foliar N and Ca concentrations. Needle C:N ratios increased with higher temperature, acidifying depositions and precipitation. By linking these patterns to seed viability, we found that low needle P, Ca and Mg concentrations were related to low seed viability. Thus, a shortage of these key elements during seed development and seed nutrient storage, can lead to anomalies and seed abortion. These findings help to explain the low seed viability of juniper in Europe and may help to assist land managers to take urgently needed conservation actions.     

共表达口蹄疫病毒衣壳前体蛋白P1-2A基因和蛋白酶3C基因牛肾细胞株的筛选及稳定性

[目的]筛选稳定表达口蹄疫病毒衣壳蛋白的牛肾细胞(Madin-Darby bovinekidney,MDBK)株.[方法]采用聚合酶链式反应(Polymerase chain reaction,PCR)方法从重组质粒pMD-P1-2A和pMD-3C中分别扩增口蹄疫病毒衣壳前体蛋白P1-2A基因和蛋白酶3C基因,将两基因依次插入逆转录病毒载体pBABE-puro.重组逆转录病毒载体pBABE-puro/P1-2A-3C和pVSV-G质粒载体用脂质体介导共转染GP2-293包装细胞.产生的重组逆转录病毒感染MDBK细胞后使用嘌呤霉素筛选抗性细胞.利用克隆环套取法得到单克隆细胞.经间接免疫荧光和酶联免疫吸附测定(Enzyme-linkedimmunosorbent assay,ELISA)方法检测MDBK细胞中衣壳蛋白的表达,并在电镜下观察口蹄疫病毒空衣壳.[结果]成功筛选到稳定表达口蹄疫病毒衣壳蛋白的MDBK细胞株,衣壳前体蛋白P1-2A在蛋白酶3C裂解作用下正确组装成空衣壳.[结论]该研究为口蹄疫亚单位疫苗的研制提供了实验材料.     

大鼠脑内caveolin-1蛋白的表达及其在分辨学习中的作用

Caveolin-1（Cav—1）蛋白作为细胞质膜结构小窝（caveolae）的标志蛋白,在胆固醇运输、膜组装、信号转导和细胞转化过程中扮演重要的角色。为了探讨Cav-1蛋白在中枢神经系统可塑性及学习记忆中的作用,本文以Sprague—Dawley大鼠为实验对象,利用蛋白质免疫印迹杂交方法观察了Car-1蛋白在不同年龄大鼠脑内表达的特征,并研究了Y-迷宫训练前后Cav-1蛋白表达的变化。结果表明：（1）大鼠不同脑区Cav-1蛋白表达的年龄特征不同。海马内的表达属青年鼠最高,其次是老年鼠和幼年鼠;皮层内的表达属幼年鼠最高,其次是老年鼠,青年鼠最低;小脑内的表达无明显年龄差异。（2）Y-迷宫训练引起青年鼠海马和前额叶皮层内Cav-1蛋白的表达显著增加。结果提示,Cav-1蛋白与动物脑发育和学习记忆有密切关系,可能参与中枢可塑性的调节。