A20 plays a critical role in the immunoregulatory function of mesenchymal stem cells

Mesenchymal stem cells (MSCs) possess an immunoregulatory capacity and are a therapeutic target for many inflammation‐related diseases. However, the detailed mechanisms of MSC‐mediated immunosuppression remain unclear. In this study, we provide new information to partly explain the molecular mechanisms of immunoregulation by MSCs. Specifically, we found that A20 expression was induced in MSCs by inflammatory cytokines. Knockdown of A20 in MSCs resulted in increased proliferation and reduced adipogenesis, and partly reversed the suppressive effect of MSCs on T cell proliferation in vitro and inhibited tumour growth in vivo. Mechanistic studies indicated that knockdown of A20 in MSCs inhibited activation of the p38 mitogen‐activated protein kinase (MAPK) pathway, which potently promoted the production of tumour necrosis factor (TNF)‐α and inhibited the production of interleukin (IL)‐10. Collectively, these data reveal a crucial role of A20 in regulating the immunomodulatory activities of MSCs by controlling the expression of TNF‐α and IL‐10 in an inflammatory environment. These findings provide novel insights into the pathogenesis of various inflammatory‐associated diseases, and are a new reference for the future development of treatments for such afflictions.     

淫羊藿总黄酮对肾阳虚大鼠下丘脑-垂体-肾上腺轴钙调蛋白基因表达的影响

目的:从分子水平探讨肾阳虚证病理改变及淫羊藿总黄酮的作用及其机理,为开发药物的临床新用途提供理论依据.方法:用大剂量外源糖皮质激素建立肾阳虚大鼠动物模型,以实时荧光定量RT-PCR技术,测定各组大鼠下丘脑-垂体-肾上腺轴CaM mRNA的表达,以及淫羊藿总黄酮对其的影响.结果:肾阳虚大鼠下丘脑、肾上腺CaMmRNA水平升高,垂体组织CaM mRNA水平没有显著变化,淫羊藿总黄酮能够降低下丘脑组织CaM mRNA水平,但对肾上腺影响不显著.结论:大鼠肾阳虚证时下丘脑中CaM mRNA水平升高,淫羊藿总黄酮可使其降低.     

黄芪甲苷促进心肌干细胞分化的作用研究

目的 探讨黄芪甲苷对心肌干细胞分化的促进作用。方法 采用磁珠分选法,分离小鼠Sca-1＋心肌干细胞,通过免疫组化方法观察黄芪甲甙处理后心肌细胞表面标志蛋白desmin、α-sarcomeric？actin和C-TnT表达的变化,以判断是否对心肌干细胞分化有促进作用。结果 250 mg/L的黄芪甲甙诱导4周后免疫组化染色显示心肌干细胞明显表达desmin、α-sarcomeric actin和C-TnT。而未诱导的细胞desmin、α-sarcomeric actin、C-TnT 均为阴性。因此黄芪甲甙可以促进小鼠Sca-1＋心肌干细胞分化为心肌样细胞,这些细胞表达心肌特异性的蛋白。结论 黄芪甲苷对心肌干细胞分化的促进作用表明其在心肌损伤性疾病的康复中有潜在的治疗价值,值得进一步研究。     

大孔树脂提取链霉菌4903菌株除草活性物质的研究

化感活性物质的提取方法是研究化感作用的重要步骤,对化感链霉菌4903的前期研究证明其具有抑菌及除草活性。本文选用了4种大孔吸附树脂(X-5, NKA-II, AB-8和HP-20)对化感链霉菌4903发酵液的除草活性物质进行提取。实验结果显示:树脂AB-8对链霉菌4903菌株发酵液除草活性成分具有较好的吸附性能和较易被解吸的特性,树脂AB-8对链霉菌4903菌株发酵液的静态吸附量约可达到树脂体积的7倍。用树脂2-3倍体积的80%乙醇溶液则可以把吸附的除草活性物质全部从树脂中解吸出来。AB-8适合用于链霉菌4903菌株发酵液除草活性物质的提取和纯化。     

Human adipose tissue is a source of multipotent stem cells

Much of the work conducted on adult stem cells has focused on mesenchymal stem cells (MSCs) found within the bone marrow stroma. Adipose tissue, like bone marrow, is derived from the embryonic mesenchyme and contains a stroma that is easily isolated. Preliminary studies have recently identified a putative stem cell population within the adipose stromal compartment. This cell population, termed processed lipoaspirate (PLA) cells, can be isolated from human lipoaspirates and, like MSCs, differentiate toward the osteogenic, adipogenic, myogenic, and chondrogenic lineages. To confirm whether adipose tissue contains stem cells, the PLA population and multiple clonal isolates were analyzed using several molecular and biochemical approaches. PLA cells expressed multiple CD marker antigens similar to those observed on MSCs. Mesodermal lineage induction of PLA cells and clones resulted in the expression of multiple lineage-specific genes and proteins. Furthermore, biochemical analysis also confirmed lineage-specific activity. In addition to mesodermal capacity, PLA cells and clones differentiated into putative neurogenic cells, exhibiting a neuronal-like morphology and expressing several proteins consistent with the neuronal phenotype. Finally, PLA cells exhibited unique characteristics distinct from those seen in MSCs, including differences in CD marker profile and gene expression.     

用RAPD技术鉴定小麦属间不对称体细胞杂种

用随机引物扩增多态DNA(RAPD)技术对三种不同组合:小麦(Triticum aestivum)( )簇毛麦(Haynaldia villosa);小麦( )羊草(Leymus chinensis)和小麦( )高冰草(Agropyron elongatum)的属间不对称杂种进行分子鉴定,不同杂种植株的基因组经随机引物扩增后,均出现双亲的多态特异产物,证实它们含有双亲的基因组。将引物OPJ-12扩增的高冰草多态特异产物(分子量为0.77bp的DNA片段)分离纯化并标记作探针,用Southern杂交证明了小麦( )高冰草杂种经OPJ-12扩增的0.77kbp特异片段与高冰草这一片段具有同源性。本文结果证明,RAPD技术可作为小麦属间不对称体细胞杂种的一种快速、简便、有效的分子鉴定方法。     

Smad2条件基因剔除载体的构建及LoxP位点有效性鉴定

Smads家族是最新发现的TGF－β信号转导途径中一个重要的新基因家族,SMAD2属于受体激活的SMADs。Smad2在某些肿瘤中发生突变,是一种可能的肿瘤抑制基因。Smad2基因完全剔除小鼠在胚胎期E6．5天死亡,为了研究Smad2在成体各组织器官及肿瘤发生中的可能作用,构建了Smad2条件基因剔除载体,将LoxP置于Smad2基因组序列C末端功能域两侧,并在组成型表达Cre重组酶的大肠杆菌中检测了LoxP位点的功能,该载体的构建为进行Smad2组织特异性基因剔除研究了奠定了基础。     

Aβ42转基因AD果蝇的构建及在药物筛选中的运用

阿尔茨海默病（Alzheimer’s disease,AD）是一种以β-淀粉样蛋白的形成和沉积为主要特征的神经退行性疾病,Aβ42被认为在AD的发病过程中起着重要的作用。果蝇是一种遗传操作简便的模式动物,利用果蝇中经典的Gal4／UAS系统,作者构建了在中枢神经系统中全神经元或运动神经元表达单拷贝或双拷贝AB42的转基因AD果蝇,并检验转基因果蝇在AD治疗药物筛选中的作用。结果显示,转基因AD果蝇寿命明显缩短且运动能力降低,而使用AD临床治疗药物安理申后,可延长AD果蝇寿命,改善AID果蝇的运动障碍。进一步的研究显示,δ阿片受体拮抗剂naltrindole给药后,也能缓解这些症状。该研究为AD治疗药物的初筛提供了一个经济便捷的工具。     

Gene conjugation of molecular adjuvant C3d3 to hCGbeta increased the anti-hCGbeta Th2 and humoral immune response in DNA immunization

Human chorionic gonadotropin (hCG) has been used as an anti-fertility vaccine and as a target for cancer immunotherapy. We have explored the use of three copies of C3d in DNA vaccine as molecular adjuvant to improve the immunogenicity of this hormone in previous work and found that the immune response induced by pcDNA3-hCGbeta-C3d3 has been enhanced 243-fold compared with pcDNA3-hCGbeta following DNA immunization in BALB/c mice. In the present study, a new functionally active DNA vaccine of hCGbeta-C3d3 chimera based on pCMV4 vector has been described. We compared the expression efficiency of pCMV4 and pcDNA3 eukaryotic vectors for hCGbeta and hCGbeta-C3d3 fusion protein and the immune response of mice immunized with pcDNA3-hCGbeta, pCMV4-hCGbeta, pcDNA3-hCGbeta-C3d3 and pCMV4-hCGbeta-C3d3, respectively, at 25, 50 and 100 pmol dose, and further analyzed the levels of Th1 and Th2 cytokines produced by spleen lymphocytes of the immunized mice upon hCG restimulation in vitro. It was found that pCMV4 vector achieved 1.3-1.5-fold higher protein expression and raised 1.1-1.2 (primary) and 1.2-1.3 (booster) logs higher titer of anti-hCGbeta IgG than pcDNA3. Mice vaccinated with 50 pmol of hCGbeta-C3d3-DNAs elicited the highest titer of hCGbeta-specific antibody among the serial doses and the immune response induced by pCMV4-hCGbeta-C3d3 were, respectively, 1.3, 1.3 and 1.2 logs higher than that of pcDNA3-hCGbeta-C3d3 and 2.2, 2.9 and 2.4 logs higher than that of pCMV4-hCGbeta at week 2 following the booster immunization. Moreover, we observed that the production of IL-4 and IL-10 increased in mice vaccinated with hCGbeta-C3d3-DNAs and the ratio of IL-4/IFN-(gamma) showed a Th2 bias of immune response in the mice immunized with hCGbeta-C3d3-DNAs. These findings indicated that gene fusion of C3d3 to hCGbeta, as a means of harnessing the adjuvant potential of the innate immune system, may improve the antigen-specific Th2 humoral immune response of the hCGbeta DNA vaccine and the pCMV4 vector is a more ideal eukaryotic vector for DNA vaccine than pcDNA3.     

拟南芥细胞中存在中间纤维的研究

利用整装电镜制样与选择性抽提技术,在拟南芥（Ａｒａｂｉｄｏｐｓｉｓｔｈａｌｉａｎａ （Ｌ．） Ｈｅｙｎｈ） 愈伤组织细胞质中观察到直径１０ ｎｍ 左右的纤维网络结构。免疫印迹分析表明纤维的主要成分是６ 种多肽,它们分别与动物角蛋白单克隆抗体ＡＥ１ 、ＡＥ３ 有免疫交叉反应。利用间接免疫荧光技术,与ＡＥ１ 和ＡＥ３ 反应的抗原呈弥散状定位于整个细胞质中,而且１０ ｎｍ 纤维可以在体外重新组装。以上结果表明,在拟南芥细胞质中存在类角蛋白的中间纤维。以动物中间纤维基因的保守序列为引物,采用ＲＴ＿ＰＣＲ技术,进一步从这一模式植物中克隆到一个ｃＤＮＡ片段,这可能为从分子水平上证明植物中间纤维的存在提供了一个线索