Identification of five human novel genes associated with cell proliferation by cell-based screening from an expressed cDNA ORF library

The development of functional profiling technologies provides opportunity for high-throughput functional genomics studies. We describe a cell-based screening system to identify novel human genes associated with cell proliferation. The method integrates luciferase reporter gene activity, fluorescence stain, automated microscopy and cellular phenotype assays. We successfully used the system to screen 409 novel human genes cloned by our lab and found that 27 genes significantly up-regulated promoter-Renilla luciferase reporter plasmid (pRL) activity. Among them, five genes, TRAF3IP3, ZNF306, ZNF250, SGOL1, and ZNF434, were determined through morphological observation, calcein AM fluorescence stain, MTT assay and cell cycle analysis to be associated with cell proliferation. Furthermore, we showed that the gene TRAF3IP3, which initially was identified to specifically interact with TRAF3, stimulated cell growth by modulating the c-Jun N-terminal kinase (JNK) pathway, and RNAi of TRAF3IP3 confirmed that the effect was physiological and necessary. In summary, we integrated a rapid and efficient system for screening novel growth regulatory genes. Using the new screening system we identified five genes associated with cell proliferation for the first time.     

木本植物非均质化组织石蜡切片制作方法

在常规石蜡切片技术的基础上, 针对木本植物茎段木质化程度高、硬度大以及各部分组织硬度不均匀等特点, 选取核桃(Juglans regia)茎段以及芽接愈合区域组织为实验材料, 对固定、软化和脱水等关键步骤进行改进, 获得结构完整且染色清晰的茎段组织和嫁接愈合区域组织切片, 可清晰地观察到各部分组织的形态特征和愈合过程中的发育特征, 且缩短了制片周期。采用改良后的实验流程成功获得了苹果(Malus pumila)、桃(Amygdalus persica)、杏(Armeniaca vulgaris)、李(Prunus salicina)和杨(Populus tomentosa)的茎段横截面切片。该方法为从解剖学上研究林木茎段生长机制和形态发育变化提供技术基础, 为非均质化植物材料的石蜡切片制作提供参考。     

SAG, a novel zinc RING finger protein that protects cells from apoptosis induced by redox agents

SAG (sensitive to apoptosis gene) was cloned as an inducible gene by 1,10-phenanthroline (OP), a redox-sensitive compound and an apoptosis inducer. SAG encodes a novel zinc RING finger protein that consists of 113 amino acids with a calculated molecular mass of 12.6 kDa. SAG is highly conserved during evolution, with identities of 70% between human and Caenorhabditis elegans sequences and 55% between human and yeast sequences. In human tissues, SAG is ubiquitously expressed at high levels in skeletal muscles, heart, and testis. SAG is localized in both the cytoplasm and the nucleus of cells, and its gene was mapped to chromosome 3q22-24. Bacterially expressed and purified human SAG binds to zinc and copper metal ions and prevents lipid peroxidation induced by copper or a free radical generator. When overexpressed in several human cell lines, SAG protects cells from apoptosis induced by redox agents (the metal chelator OP and zinc or copper metal ions). Mechanistically, SAG appears to inhibit and/or delay metal ion-induced cytochrome c release and caspase activation. Thus, SAG is a cellular protective molecule that appears to act as an antioxidant to inhibit apoptosis induced by metal ions and reactive oxygen species.     

肠道菌群与心血管疾病和血管钙化相关性的研究进展

心血管疾病是我国乃至全球的主要死亡原因。血管钙化是公认的心血管疾病发生的危险因素,表现为血管平滑肌细胞表型改变和/或动脉粥样硬化,最终导致血管僵硬,显著增加心血管疾病的发病率。近年来,肠道菌群作为包括心血管疾病在内的多种疾病发病机制的潜在可变因素之一,受到越来越多的关注。多项研究已揭示肠道菌群及其代谢产物在宿主心血管疾病（如冠状动脉粥样硬化、高血压、心力衰竭和心律失常等）发生和发展中的作用。本文就肠道菌群如何影响心血管疾病尤其是与血管钙化相关性的研究进展作一综述。

     

臭氧浓度升高对香樟叶片光合色素及抗过氧化的影响及其氮素响应

为阐明氮(N)沉降条件下我国亚热带典型常绿树种香樟(Cinnamomum camphora)的臭氧(O3)胁迫响应特征,以1年生幼苗为试验对象,采用开顶气室(OTC)进行模拟研究。O3处理设大气O3(AA)、大气O3+60 nmol/mol(AA+60)、大气O3+120nmol/mol(AA+120)3个水平;N素以硝酸铵(NH4NO3)溶液形式施加,施N量设0(N0)、30(N30)、60(N60)(kg.hm-.2a-1)3个水平。主要考察了叶片膜质过氧化、光合色素、胞质抗坏血酸含量及总抗氧化能力的胁迫响应特征。结果表明:一个生长季(2009年5月15日—2009年9月10日)高浓度O3处理导致试验幼苗叶肉细胞膜脂过氧化程度显著加剧,叶绿素a、叶绿素b、类胡萝卜素含量显著降低;N素施加显著提高了叶绿素含量,但未改变细胞膜脂过氧化水平。叶片总抗氧化能力在AA+120处理下显著提高,但未受N施加影响。还原型抗坏血酸含量在N0处理下随O3浓度升高而降低;在N30及N60处理下随O3浓度升高而增高。施N可通过提高叶片抗坏血酸含量来增强香樟对O3升高的适应能力。研究结论可为O3与N复合污染下,我国亚热带地区典型常绿树种的保护提供科学参考。     

一种受抗生素诱导的启动子的构建及活性分析

多聚ADP核糖聚合酶（PARP）受基因毒剂的特异性诱导。将拟南芥（Arabidopsis thaliana）AtPARP1基因上游长2179bp的启动子片段插入到质粒pAKK687的β-葡萄糖醛酸糖苷酶（GUS）报告基因上游,转化拟南芥。GUS组织化学染色结果表明,GUS报告基因仅在苗龄3-5天的拟南芥根部及花发育早期的雄蕊中表达;1.5μg.mL-1博莱霉素与22μg.mL-1丝裂霉素联用强烈诱导了GUS报告基因的表达（尤其在拟南芥的幼苗和果荚中）。进一步降低抗生素浓度,发现单独使用1μg.mL-1博莱霉素对GUS报告基因也具较强的诱导活性,且对拟南芥幼苗的生长无影响。上述结果表明,AtPARP1启动子是一个新型的具较大应用潜力的抗生素诱导型启动子。