Leucine-rich repeat C4 protein is involved in nervous tissue development and neurite outgrowth, and induction of glioma cell differentiation

LRRC4, leucine-rich repeat C4 protein, has been identified in human （GenBank accession No. AF196976）, mouse （GenBank accession No. DQ177325）, rat （GenBank accession No. DQ119102） and bovine （GenBank accession No. DQ 164537） with identical domains. In terms of their similarity, the genes encoding LRRC4 in these four mammalian species are orthogs and therefore correspond to the same gene entity. Based on previous research, and using in situ hybridization, we found that LRRC4 had the strongest expression in hippocampal CA1 and CA2, the granule cells of the dentate gyrus region, the mediodoral thalamic nucleus, and cerebella Purkinje cell layers. Using a P19 cell model, we also found that LRRC4 participates in the differentiation of neuron and glia cells. In addition, extracellular proteins containing both an LRR cassette and immunoglobulin domains have been shown to participate in axon guidance. Our data from neurite outgrowth assays indicated that LRRC4 promoted neurite extension of hippocampal neurons, and induced differentiation of glioblastoma U251 cells into astrocyte-like cells, confirmed by morphology observation and glial fibrillary acidic protein expression.     

The PKC delta inhibitor, rottlerin, induces apoptosis of haematopoietic cell lines through mitochondrial membrane depolarization and caspases' cascade

Rottlerin is a widely selective protein kinase C delta (PKCdelta) inhibitor isolated from Mallotus philippinensis. It shown to be effective against several human tumor cell lines and in potentiating chemotherapy-induced cytotoxcicity. Using the trypan blue exclusion assay, we demonstrated that rottlerin reduced the viability in a dose- and time-dependent manner of human leukemia HL60 cells, human acute T cell leukemia Jurkat cells and mouse macrophage RAW 264.7 cells. Rottlerin caused apoptosis and the apaptotic processing was inhibited by a caspase inhibitor, z-VAD-fmk, in these haematopoietic cells. The apoptosis-inducing activities were determined by nuclear condensation, sub-G1 appearance, DNA fragmentation, loss of mitochondrial membrane potential (Deltapsim), release of mitochondrial cytochrome c into cytoplasm and proteolytic activation of caspase 9 and 3. Expression of PKCdelta and Bcl-2 protein inhibited Deltapsim change and repressed cell death. These studies suggest that the cytotoxic effects of rottlerin through inhibition of PKCdelta cause mitochondrial dysfunction, cytochrome c release from mitochondria into cytoplasm and the activation of caspases' cascade.     

江西省8种外来植物分布新记录

According to field investigation results, specimen identification and related literatures, eight newly recorded species of alien plants in Jiangxi Province were defined, viz. Amaranthus palmeri S. Watson, Oenothera laciniata Hill, Jacquemontia tamnifolia ( Linn.) Griseb., Ipomoea lacunosa Linn., Solanum sisymbriifolium Lam., Triodanis perfoliata (Linn.) Nieuwl., Erigeron philadelphicus Linn. and Bromus catharticus Vahl. These species have already established population in Jiangxi Province, and some have been invaded. Voucher specimens are deposited in Shanghai Chenshan Herbarium ( CSH) .     

海南地区与环渤海湾美人鱼发光杆菌美人鱼亚种水产动物分离株的表型与遗传特征分析

美人鱼发光杆菌美人鱼亚种(Photobacterium damselae subsp.damselae,PDD)是一种广泛分布于海洋环境内的重要病原菌,可导致多种海洋生物患病死亡,近年来在我国不同养殖区域内均有发现和报道.[目的]通过生理代谢表型、毒力基因分布和分子遗传分析,系统比较我国海南地区和环渤海湾不同株系PDD...     

在基于BAC的EB病毒基因组中引入突变

为了在Epstein-Barr病毒(EBV)172kb的基因组中引入突变以研究基因功能,建立了一种简单有效的基因操作方法.在载体pcDNA3.1( )上操作,将两端含有重组蛋白FLP识别位点(FRT)的卡那霉素筛选标记基因(kan)与鼻咽癌(NPC)来源的、包含LMP1基因全长ORF的gDNA"无缝"连接(无外源序列插入).连接后的kan-LMP1线性DNA片段经转化、由λ噬菌体中redαβγ系统介导在E.coli中发生同源重组(ET克隆),用kan-LMP1替代了BAC-EBV(p2089)中相应的LMP1基因区域,然后经过重组蛋白FLP对FRT-kan-FRT特异性的识别,切除了引入的kan基因,留下一个69bp的FRT"疤痕".通过抗性筛选和对菌液进行PCR扩增可以鉴定突变子.这种经改进并程序化的方法.也适应于引入其它突变或在其它BAC-疱疹病毒基因组中引入突变.     

高效液相色谱法分离和鉴定腐马素B_1

腐马素是由串珠镰刀菌产生的真菌毒素,其中腐马素B1可引发马脑白质软化症等疾病。本文用高效液相色谱法从串珠镰刀菌玉米培养物中分离出了腐马素B1并通过紫外光谱和快原子轰击质谱进行了鉴定。     

Adhesion of lymphoid cell lines to fibronectin-coated substratum: Biochemical and physiological characterization and the identification of a 140-kDa fibronectin receptor

Little information is available on the interaction between lymphocytes and fibronectin (fn). To gain a better understanding on this issue we examined the adhesion of 12 lymphoid cell lines, each exhibiting different phenotypic characteristics, to fn-coated substratum. Of the cell lines tested, five that adhered to fn possessed B-cell characteristics, while neither the T-cell lines nor the pre-B-cell line adhered. The physiology and biochemistry of adhesion of a B-cell line, MOPC 315, were examined in detail. Our results indicated that (1) the adhesion was a specific and time-dependent process, (2) the adhesion was temperature-dependent and inhibited by metabolic inhibitors, such as KCN and 2-deoxyglucose, (3) the presence of cycloheximide and pretreatment of cells with trypsin inhibited adhesion, (4) a 140-kDa surface protein was immunoprecipitated by anti-fn receptor antibodies, (5) the presence of divalent cations was essential for adhesion, (6) the presence of colchicine had no effect on adhesion, while cytochalasin B partially inhibited adhesion, and (7) the treatment of cells by both phorbol 12-myristate 13-acetate and calcium ionophore A23187 enhanced adhesion. In this study, we have established the interaction between lymphoid cell lines and fn. Such an interaction might play an important role in the behavior of lymphocytes in tissues.     

鄂西南国家级自然保护区群——苔藓植物多样性保护的重要场所

鄂西南地区密集分布有后河、木林子、七姊妹山和星斗山四大国家级自然保护区,共同形成了一个珍稀动植物大体相近、互相补充的保护区群,为摸清鄂西南保护区群的苔藓植物组成,该文采用野外调查和文献资料整理相结合的方法,对鄂西南国家级自然保护区群内的苔藓植物丰富度和组成特征进行了分析,并与渝东南、湘西北的苔藓植物多样性进行了比较.结...