双向凝胶电泳-飞行时间质谱技术鉴定小鼠胚泡黏附时子宫内膜nm23-M2／NDPK B的表达

运用双向聚丙烯酰胺凝胶电泳(2DPAGE)分析未交配小鼠子宫内膜和妊娠第五天(D5)小鼠子宫内膜胚泡黏附时植入位点及其旁组织蛋白质组。差异蛋白质组学显示,等电点(isoelectric point,pI)约7．1、分子量(molecular weight,Mw)约18kDa的蛋白质点在D5小鼠子宫内膜特别是植入位点表达上调。对此蛋白质点用基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption／ionization time of flying mass spectrometry,MALDI—TOF—MS)测定其胶内酶解后的肽质量指纹谱(Peptide Mass Fingerprint,PMF),经Mascot：Peptide Mass Fingerprint中SWISS-PROT数据库查询后,鉴定该蛋白质为鼠源性nm23-M2／NDPKB。RT—PCR和免疫组织化学结果也显示D5小鼠子宫内膜nm23-M2／NDPK B mRNA和蛋白表达明显增加。提示nm23-M2／NDPKB参与胚泡着床这一重要生命活动过程。     

Lack of apoE causes alteration of cytokines expression in young mice liver

To investigate the effect of apolipoprotein E (apoE) on cytokine expression profile of the liver of young mice, quantitative RT-PCR (qRT-PCR) assay and cytokine antibody array for multiplex analysis of 62 cytokines have been used to analyze characteristics of expression of cytokines in the liver of 6-week-old apoE-null (apoE^−/−) mice. The levels of plasma cytokines were also analyzed. The mRNA level of IL-1β, IL-2, IL-6, ICAM-1, VCAM-1, MCP-1, NF-κB (p65), IFN-γ and IκB-α were increased significantly in apoE^−/− mice comparative to wild-type (WT) mice. IL-4, IL-10 and GM-CSF, however, were slightly decreased. Compared with WT, levels of 21 cytokines altered twofold or more in apoE^−/− mice, including 10 cytokines increased and 11 decreased. Expression patterns of IL-1β, IL-2, IL-4, IL-6, IL-10, GM-CSF, IFN-γ and VCAM-1 showed identical trend between cytokine antibody array and qRT-PCR analysis. Moreover, levels of IL-1β, IFN-γ and IL-6 in the plasma were elevated, while IL-4 was lightly decreased in apoE^−/− mice compared to those in WT mice. These results implied that promotion of type I immune response in the liver of young apoE^−/− mice due to alteration of these cytokines, and the phenotypes may be caused by the regulation of NF-κB. The inflammation and lipid metabolism dysfunction in the liver cooperated in dysfunction of the liver in young apoE^−/− mice.     

Incorporating biological knowledge into distance-based clustering analysis of microarray gene expression data

MOTIVATION: Because co-expressed genes are likely to share the same biological function, cluster analysis of gene expression profiles has been applied for gene function discovery. Most existing clustering methods ignore known gene functions in the process of clustering. RESULTS: To take advantage of accumulating gene functional annotations, we propose incorporating known gene functions into a new distance metric, which shrinks a gene expression-based distance towards 0 if and only if the two genes share a common gene function. A two-step procedure is used. First, the shrinkage distance metric is used in any distance-based clustering method, e.g. K-medoids or hierarchical clustering, to cluster the genes with known functions. Second, while keeping the clustering results from the first step for the genes with known functions, the expression-based distance metric is used to cluster the remaining genes of unknown function, assigning each of them to either one of the clusters obtained in the first step or some new clusters. A simulation study and an application to gene function prediction for the yeast demonstrate the advantage of our proposal over the standard method.     

Self-renewal and Differentiation of Muscle Satellite Cells Are Regulated by the Fas-associated Death Domain

Making the decision between self-renewal and differentiation of adult stem cells is critical for tissue repair and homeostasis. Here we show that the apoptotic adaptor Fas-associated death domain (FADD) regulates the fate decisions of muscle satellite cells (SCs). FADD phosphorylation was specifically induced in cycling SCs, which was high in metaphase and declined in later anaphase. Furthermore, phosphorylated FADD at Ser-191 accumulated in the uncommitted cycling SCs and was asymmetrically localized in the self-renewing daughter SCs. SCs containing a phosphoryl-mimicking mutation at Ser-191 of FADD (FADD-D) expressed higher levels of stem-like markers and reduced commitment-associated markers. Moreover, a phosphoryl-mimicking mutation at Ser-191 of FADD suppressed SC activation and differentiation, which promoted the cycling SCs into a reversible quiescent state. Therefore, these data indicate that FADD regulates the fate determination of cycling SCs.     

脱氧核酶的研究进展

具有RNA裂解活性的DNA分子称为脱氧核酶。它是经过体外选择技术经多次筛选获得的。脱氧核酶在切割与其互补的RNA底物分子时具有极高的特异性和切割效率,有望成为新的RNA灭活工具。     

5-酮基-D-葡萄糖酸发酵生产的工艺条件优化

葡萄糖酸氧化杆菌可将葡萄糖转化为5-酮基-D-葡萄糖酸(5-KGA),而5-KGA是重要食品添加剂L(+)-酒石酸的合成前体。为提高5-KGA产量及其对葡萄糖的转化率,对5-KGA发酵生产的工艺条件进行优化。在摇瓶水平最适的培养基和培养条件下,5-KGA最高产量为19.7 g/L,较优化前提高43.8%。在5 L发酵罐上控制恒定pH值5.5、溶氧浓度15%条件下,5-KGA产量达到46.0 g/L,较摇瓶最高产量提高1.3倍,应用葡萄糖流加工艺,5-KGA最高产量达到75.5 g/L,转化率超过70%,与已见报道的最高水平相比提高了32.0%,为实现微生物发酵生产5-KGA、进而合成L(+)-酒石酸的工业化提供了切实有效的途径。