Inhibition of PLK4 might enhance the anti-tumour effect of bortezomib on glioblastoma via PTEN/PI3K/AKT/mTOR signalling pathway

Glioblastoma (GBM) is one of the most common aggressive cancers of the central nervous system in adults with a high mortality rate. Bortezomib is a boronic acid–based potent proteasome inhibitor that has been actively studied for its anti-tumour effects through inhibition of the proteasome. The proteasome is a key component of the ubiquitin-proteasome pathway that is critical for protein homeostasis, regulation of cellular growth, and apoptosis. Overexpression of polo-like kinase 4 (PLK4) is commonly reported in tumour cells and increases their invasive and metastatic abilities. In this study, we established a cell model of PLK4 knockdown and overexpression in LN-18, A172 and LN-229 cells and found that knockdown of PLK4 expression enhanced the anti-tumour effect of bortezomib. We further found that this effect may be mediated by the PTEN/PI3K/AKT/mTOR signalling pathway and that the apoptotic and oxidative stress processes were activated, while the expression of matrix metalloproteinases (MMPs) was down-regulated. Similar phenomenon was observed using in vitro experiments. Thus, we speculate that PLK4 inhibition may be a new therapeutic strategy for GBM.     

Estimating heat flux transmission of vertical greenery ecosystem

Nurturing vegetation on building envelopes provides an innovative and eco-friendly alternative to urban greening especially in compact cities. Whereas the thermal and other benefits of green roofs have been studied intensively, green walls have received scanty attention. This study evaluates the thermodynamic transmission process of the vertical greenery ecosystem. We designed a field experiment to monitor solar radiation and weather conditions, and developed a thermodynamics transmission model to simulate heat flux and temperature variations. The model was calibrated, tested, and proved to be highly efficient. The results show that seasonal global and direct solar radiation drops to minimum in winter in January and February, and reaches maximum in summer in July and August (1168 W m⁻² for global solar radiation and 889 W m⁻² for direct solar radiation). Diffuse solar radiation attains maximum in summer (586 W m⁻²) with moderate rainfall in July and August, and minimum in winter with no rainfall in January and February. Radiation transmission of the green wall strongly correlates with canopy transmittance and reflectance (R² = 0.83). Thermal shielding effectiveness varies with orientation, with the south wall achieving a higher coefficient (0.31) than the north wall. The south wall has lower heat flux absorbance and heat flux loss than the north wall. The south wall can transfer much more heat flux through the vertical greenery ecosystem due to more intensive canopy evapotranspiration effect. The model matches the transmission properties of green wall radiation, and the model simulation fits empirical transmission results.     

泛素化和SUMO化对DEC1的拮抗调控作用

分化的胚软骨表达蛋白1(differentiated embryo-chondrocyte expressed gene 1,DEC1)作为一种时钟蛋白,除了在周期节律的调控中发挥转录抑制作用外,还在能量代谢以及多种肿瘤相关的信号通路的调控中发挥重要作用。此外,蛋白质的翻译后修饰是实现蛋白质功能精细调控的一种重要方式。目前发现,DEC1主要可被两种翻译后修饰,即泛素化和SUMO化修饰。尽管泛素化和SUMO化是两种过程非常类似的蛋白质翻译后修饰方式,但是它们对目的蛋白功能的调控却截然不同。由于泛素化和SUMO化与底物的作用靶点都是赖氨酸(Lys),因此在多数情况下,泛素化和SUMO化以拮抗性的方式调控底物蛋白的功能。鉴于此,该文旨在阐述泛素化和SUMO化修饰对DEC1功能的拮抗调节过程,为了解时钟蛋白DEC1对多种信号通路的调控过程中的分子机制提供新的思路。     

Synthesis and characterisation of novel chromogenic substrates for human pancreatic alpha-amylase

Derivatives of maltose and maltotriose were chemically synthesised as substrates for human pancreatic alpha-amylases and subjected to kinetic analysis. Rates measured were shown to reflect both hydrolysis and transglycosylation reactions. 4-O-Methylated derivatives of these substrates underwent only hydrolysis, thereby simplifying kinetic analyses. These modified substrates may be used for the detection and kinetic analysis of alpha-amylases, and are useful in rapidly screening for novel alpha-amylase inhibitors and for subsequent kinetic characterisation.     

Illumina-Based Sequencing Analysis Directed Selection for Actinobacterial Probiotic Candidates for Banana Plants

As potential probiotic candidates, plant vertically transmitted actinobacteria are beneficial to growth and health of host plants. New methods to isolate the actinobacterial taxa with low growth rates should be developed. Based on the actinobacterial population information, the probiotic actinobacterial taxa could be directly isolated from healthy banana shoot tips. However, actinobacterial DNAs with high GC contents could bias estimates of actinobacteria by PCR. In the study, two amplicon sequencing strategies were adopted to elucidate the endophytic actinobacterial community of banana plants. More than 92.5% bacterial OTUs were affiliated with actinobacteria by these two strategies, and total 14,289 actinobacterial OTUs with above 97% similarity were detected in banana shoot tips. Although the libraries generated by the two strategies differed in the abundance of some genera, Mycobacterium and Nocardia dominated both libraries and most actinobacterial taxa were overlapped. Higher phylogenetic resolution actinobacteriome of banana plants was successfully established. Based on the endophytic actinobacterial community information, the streptomycetes were isolated from shoot tips. Pot experiments illustrated that the strain could promote banana plantlet growth and elevate resistance to Fusarium oxysporum f. sp. cubense (FOC) under FOC infested soils. The results suggested that the selection for probiotic agents based on actinobacteriome analysis is reliable and feasible compared with present greenhouse selection.     

Evaluation of the Diversity of Probiotic <Emphasis Type="Italic">Bacillus</Emphasis>, <Emphasis Type="Italic">Clostridium</Emphasis>, and <Emphasis Type="Italic">Bifidobacterium</Emphasis> Using the Illumina-Based Sequencing Method

Bacterial species of Bacillus, Lactobacillus, and Bifidobacterium in the intestinal tract have been used as probiotics. Selections for probiotic candidates by the culture-based approaches are time-consuming and labor-consuming. The aim of this study was to develop a new method based on sequencing strategies to select the probiotic Bacillus, Lactobacillus, and Bifidobacterium. The Illumina-based sequencing strategies with different specific primers for Bacillus, Clostridium, and Bifidobacterium were applied to analyze diversity of the genera in goat feces. The average number of different Bacillus, Clostridium, and Bifidobacterium OTUs (operational taxonomic units) at the 97% similarity level ranged from 1922 to 63172. The coverage index values of Bacillus, Clostridium, and Bifidobacterium calculated from the bacterial OTUs were 0.89, 0.99, and 1.00, respectively. The most genera of Bacillus (37.9%), Clostridium (53%), and Bifidobacterium (99%) were detected in goat feces by the Illumina-based sequencing with the specific primers of the genera, respectively. Higher phylogenetic resolutions of the genera in goat feces were successfully established. The results suggest that the selection for probiotic Bacillus, Clostridium, and Bifidobacterium based on the Illumina sequencing with their specific primers is reliable and feasible, and the core Bacillus, Clostridium, and Bifidobacterium species of healthy goats possess the potentials as probiotic microbial consortia.     

HLA系统D区基因分型和中国汉族人特有的RFLP

HLA II类抗原在外来抗原提呈中起重要作用,在DNA水平进行II类抗原基因分型有更强的多态性鉴别能力,有利于检出新的特异性,根据白种人纯合分型细胞（HTC）和中国人部分纯合细胞DRB和DQA基因的RFLP格局,我们对上海地区90名随机健康人进行了HLA－D区基因分型,并将结果与血清学分型相比较,证明了它的可靠性和优越性。此外,通过与白种人格局相比,我们还发现了中国人特有的HLA－D区RFLP格局。     

我国汉族和彝族rRNA基因多态性的研究

人类ｒＤＮＡ顺序既偏偏保守性积蓄高的转录区,又有变异性较大的不转录间隔区。随着对ｒＤＮＡ结构的不断认识,发现对不转录间隔区特征的研究在分子群体遗传学上具有重要的价值。我们运用ｒＤＮＡ基因探针和Ｓｏｕｔｈｅｒｎ印迹法对甸汉族和彝族ｒＲＮＡ基因３＇端不转录间隔区作多态性分析,ＲＦＬＰ特征揭示两个民族有广泛的共性,又有各自的特点,这一遗传标志对少数民族群体遗传学乃至我国民族的迁移和演化的研究有重要意义。     

作物品种区试场点试验效果评价方法的探讨

本文对作物品种区域试验中各试验场点多年非平衡数据,提出了相应的数学模型和统计方法．以渐江省晚粳（糯）稻品种区域试验资料为例作了分析,并对区试中各试验场点评价指标作了探讨．分析结果表明,浙江省晚粳（糯）稻品种1989～1995年区域试验中,以渐江省诸暨稻麦原种场、舟山试验点综合评价效果最好,其次是富阳、龙泉、台州、宁波、衢州试验点．