RNA-binding proteins in neurological diseases

Emerging studies support that RNA-binding proteins(RBPs)play critical roles in human biology and pathogenesis.RBPs are essential players in RNA processing and metabolism,including pre-mRNA splicing,polyadenylation,transport,surveillance,mRNA localization,mRNA stability control,translational control and editing of various types of RNAs.Aberrant expression of and mutations in RBP genes affect various steps of RNA processing,altering target gene function.RBPs have been associated with various diseases,including neurological diseases.Here,we mainly focus on selected RNA-binding proteins including Nova-1/Nova-2,HuR/HuB/HuC/HuD,TDP-43,Fus,Rbfox1/Rbfox2,QKI and FMRP,discussing their function and roles in human diseases.     

Distribution and characteristics of telocytes as nurse cells in the architectural organization of engineered heart tissues

Interstitial Cajal-like cells are a distinct type of interstitial cell with a wide distribution in mammalian organs and tissues,and have been given the name"telocytes".Recent studies have demonstrated the potential roles of telocytes in heart development,renewal,and repair.However,further research on the functions of telocytes is limited by the complicated in vivo environment.This study was designed to construct engineered heart tissue(EHT)as a three-dimensional model in vitro to better understand the role of telocytes in the architectural organization of the myocardium.EHTs were constructed by seeding neonatal cardiomyocytes in collagen/Matrigel scaffolds followed by culture under persistent static stretch.Telocytes in EHTs were identified by histology,toluidine blue staining,immunofluorescence,and transmission electron microscopy.The results from histology and toluidine blue staining demonstrated widespread putative telocytes with compact toluidine blue-stained nuclei,which were located around cardiomyocytes.Prolongations from the cell bodies showed a characteristic dichotomous branching pattern and formed networks in EHTs.Immunofluorescence revealed positive staining of telocytes for CD34 and vimentin with typical moniliform prolongations.A series of electron microscopy images further showed that typical telocytes embraced the cardiomyocytes with their long prolongations and exhibited a marked appearance of nursing cardiomyocytes during the construction of EHTs.This finding highlights the great importance of telocytes in the architectural organization of EHTs.It also suggests that EHT is an appropriate physical and pathological model system in vitro to study the roles of telocytes during heart development and regeneration.     

＂Unconventional＂ Neutralizing Activity of Antibodies Against HIV

Neutralizing antibodies are recognized to be one of the essential elements of the adaptive immune response that must be induced by an effective vaccine against HIV. However,only a limited number of antibodies have been identified to neutralize a broad range of primary isolates of HIV-1 and attempts to induce such antibodies by immunization were unsuccessful. The difficulties to generate such antibodies are mainly due to intrinsic properties of HIV-1 envelope spikes,such as high sequence diversity,heavy glycosylation,and inducible and transient nature of certain epitopes. In vitro neutralizing antibodies are identified using "conventional" neutralization assay which uses phytohe-magglutinin (PHA)-stimulated human PBMCs as target cells. Thus,in essence the assay evaluates HIV-1 replication in CD4 T cells. Recently,several laboratories including us demonstrated that some monoclonal antibodies and HIV-1-specific polyclonal IgG purified from patient sera,although they do not have neutralizing activity when tested by the "conventional" neutralization assay,do exhibit potent and broad neutralizing activity in "unconventional" ways. The neutralizing activity of these antibodies and IgG fractions is acquired through post-translational modifications,through opsonization of virus particles into macrophages and immature dendritic cells (iDCs),or through expression of antibodies on the surface of HIV-1-susceptible cells. This review will focus on recent findings of this area and point out their potential applications in the development of preventive strategies against HIV.     

Evolutionary relationships of Pemphigus and allied genera （Hemiptera： Aphididae： Eriosomatinae） and their primary endosymbiont,Buchnera aphidicola

Aphids harbor primary endosymbionts, Buchnera aphidicola, in specialized cells within their body cavities. Aphids and Buchnera have strict mutualistic relationships in nutrition exchange. This ancient association has received much attention from researchers who are interested in endosymbiotic evolution. Previous studies have foundparallel phylogenetic relationships between non-galling aphids and Buchnera at lower taxonomic levels （genus, species）. To understand whether relatively isolated habitats such as galls have effect on the parallel relationships between aphids and Buchnera, the present paper investigated the phylogenetic relationships of gall aphids from Pemphigus and allied genera, which induce pseudo-galls or galls on Populus spp. （poplar） and Buchnera. The molecular phylogenies inferred from three aphid genes （COI, COII and EF-la） andtwo Buchnera genes （gnd, 16S rRNA gene） indicated significant congruence between aphids and Buchnera at generic as well as interspecific levels. Interestingly, both aphid andBuchnera phylogenies supported three main clades corresponding to the galling locations of aphids, namely leaf, the joint of leaf blade and petiole, and branch of the host plant.The results suggest phylogenetic conservatism of gall characters, which indicates gall characters are more strongly affected by aphid phylogeny, rather than host plants.     

Production of Polyamines Is Enhanced by Endogenous Abscisic Acid in Maize Seedlings Subjected to Salt Stress

It is known that salt stress and exogenously applied abscisic acid （ABA） can enhance the polyamine content in plants and that salt stress itself can lead to an increase in endogenous ABA production. In the present study, the relationships between salt-induced ABA and polyamine accumulation were inves- tigated using ABA-deficient mutant （vp5/vp5） maize （Zea mays L.） seedlings and ABA and polyamine biosynthesis inhibitors. The results show that reduced endogenous ABA levels, as a result of either the mutation or by using a chemical inhibitor （sodium tungstate）, also reduced the accumulation of polyamines in salt-stressed leaves of maize seedlings. The polyamine synthesis inhibitors D-arginine and α- difluoromethylornithine also reduced the polyamine content of the leaves of maize seedling under salt stress. Both ABA and polyamine enhanced the dry weight accumulation of salt-stressed seedlings and also increased the activities of the two dominant tonoplast membrane enzymes, H^＋-ATPase and H^＋-PPase, when plants were under salt stress. The results suggest that salt stress induces an increase in endogenous ABA levels, which then enhances polyamine synthesis. Such responses may increase a plant＇s tolerance to salt.     

Evolutionary trace analysis of eukaryotic DNA topoisomerase I superfamily: Identification of novel antitumor drug binding site

During protein evolutionary processes, protein fam-ily members undergo extensive random mutations and a long period of natural selections, and thus induce the functional evolution and the emergence of subfamily. The evolutionary variation events were recorded in the sequences of protein family members. Therefore, identification of functionally important residues can be achieved by studying residue conservation in protein sequence families. Generally, the residues conserved across the family of…     

Global human genetics of HIV-1 infection and China

Genetic polymorphisms in human genes can influence the risk for HIV-1 infection and disease progression, although the reported effects of these alleles have been inconsistent. This review highlights the recent discoveries on global and Chinese genetic polymorphisms and their association with HIV-1 transmission and disease progression.     

上海城市公共开放空间夏季小气候及舒适度

基于2006年5—8月上海城区5种类型公共开放空间（广场、喷泉、草坪、廊道、林地）的空气温度、相对湿度、风速和辐射强度等小气候指标,分析了各空间类型对小气候的调节作用,并采用体感气象指数（discomfort index, DI）作为评价指标,比较了各空间类型对人体舒适程度影响的差异.结果表明：上海市5种类型公共开放空间的平均温度、相对湿度等小气候因子存在一定差异;平均气温依次为广场＞草坪＞喷泉＞廊道＞林地;平均空气相对湿度依次为林地＞廊道＞喷泉＞草坪＞广场;广场面积、喷泉水体附近的风速及风向、草坪的草种类型、廊道的宽度及乔木盖度、林地的盖度及乔木林冠层高度等非气候指标分别与各自空间的气候指标呈显著相关.与其他3种空间类型相比,林地和廊道具有明显的遮荫、降温、增湿作用,对小气候的调节能力更佳.     

外阴阴道假丝酵母菌病的阴道清洁度观察

目的观察外阴阴道假丝酵母菌病阴道清洁度的情况。方法用湿片法进行阴道分泌物检查,随机选取1000例念珠菌阳性分泌物,对其阴道清洁度进行观察。结果1000例念珠菌阳性分泌物中,阴道清洁度Ⅳ度有606例,阴道清洁度Ⅲ度有279例,阴道清洁度Ⅱ度有82例,阴道清洁度Ⅰ度有33例。结论虽然大多数念珠菌阳性分泌物（88．5％）阴道清洁度异常（Ⅲ～Ⅳ度）,但仍然有少数念珠菌阳性分泌物（11．5％）阴道清洁度属于正常（Ⅰ～Ⅱ度）。这一结果应有助于临床妇产科医生在为患者做常规妇检、在外观性状上对阴道分泌物作判断时采取更加谨慎的态度。