水黄皮根总黄酮对大鼠乙酸型胃溃疡胃黏膜EGF及TGF-α表达的影响

目的:观察水黄皮根总黄酮(PRF)对胃溃疡大鼠乙酸型胃溃疡的作用,探讨该药促进溃疡愈合的可能机制。方法:采用乙酸注射至大鼠浆膜下形成胃溃疡模型,观察水黄皮根总黄酮对胃溃疡大鼠乙酸型胃溃疡愈合质量的影响,用放免法检测血清表皮生长因子(EGF)含量,用免疫组化法检测胃黏膜组织EGF、转化生长因子-α(TGF-α)的表达。结果:PRF能显著降低溃疡指数(P<0.05,P<0.01),提高血清中EGF含量(P<0.05,P<0.01),增强溃疡边缘胃黏膜EGF、TGF-α的表达(P<0.05,P<0.01)。结论:PRF能提高溃疡愈合质量,增强溃疡瘢痕处EGF、TGF-α的表达可能是其作用机制之一。     

A novel procedure for pre-embedding double immunogold-silver labeling at the ultrastructural level.

Pre-embedding double immunogold-silver labeling using two ultrasmall gold conjugates has not been attempted previously because a means of distinguishing labels by conjugates of identical sizes was lacking. This study investigated the feasibility of creating a particle size segregation between two ultrasmall gold conjugates through sequential immunogold incubations and silver enhancements. Two primary antibodies, mouse anti-synaptophysin and rabbit anti-glial fibrillary acidic protein (GFAP), were used in the model system. Differentiation of the double labeling was achieved by incubating with one ultrasmall gold conjugate, followed by silver enhancement, and then incubating with the second ultrasmall gold conjugate, followed by additional silver enhancement. This resulted in two groups of silver-enhanced particles: smaller particles enhanced once and larger particles enhanced twice. Electron microscopic examination revealed two readily distinguished populations of gold-silver particles within the appropriate structures, with very little size overlap. The quality of the ultrastructure permitted identification of most subcellular organelles. This procedure provides for the first time a pre-embedding immunogold-silver labeling protocol that allows the precise subcellular co-localization of multiple antigens.     

Dipsticks for rapid detection of Plasmodium in vectoring Anopheles mosquitoes

Malaria remains the most serious vector-borne disease, affecting some 300-500 million people annually, transmitted by many species of Anopheles mosquitoes (Diptera: Culicidae). Monoclonal antibodies developed against specific circumsporozoite (CS) proteins of the main malaria parasites Plasmodium falciparum and P. vivax have been used previously for enzyme-linked immunosorbent assays (ELISA), widely employed for detection of malaria sporozoites in vector Anopheles for local risk assessment, epidemiological studies and targeting vector control. However, ELISA procedures are relatively slow and impractical for field use. To circumvent this, we developed rapid wicking assays that identify the presence or absence of specific peptide epitopes of CS protein of the most important P. falciparum and two strains (variants 210 and 247) of the more widespread P. vivax. The resulting assay is a rapid, one-step procedure using a 'dipstick' wicking test strip. In laboratory assessment, dipsticks identified 1 ng/ mL of any of these three CS protein antigens, with sensitivity nearly equal to the CS standard ELISA. We have developed and are evaluating a combined panel assay that will be both qualitative and quantitative. This quick and easy dipstick test (VecTest Malaria) offers practical advantages for field workers needing to make rapid surveys of malaria vectors.     

一种新杨树菇(Agrocybe aegerita)凝集素的纯化及生化特性

用硫酸铵分级沉淀、离子交换和分子筛等方法 ,从食用菌杨树菇子实体中分离纯化了一种凝集素 ,称作为AAVP(Agrocybeaegeritaantiviralprotein) .经SDS PAGE测定其亚基的相对分子质量为15 8kD ,凝胶过滤分析分子量为 32kD .IEF PAGE计算其等电点为 3 8.AAVP不含糖 ,是一种N端焦谷氨酰环化封闭的蛋白质 ,经N端去封闭后测得N端氨基酸序列为QGVNIYNIVAGA ,用胰蛋白酶消化后得到一大片段 ,测定的氨基酸序列为PDGPWLVEK .AAVP可以凝集供试的 12种动物血和3种血型人血的血红细胞 ,但对各种血红细胞凝集滴度不同 .糖抑制实验表明 ,在供试的 18种单糖和 3种糖蛋白中 ,只有猪胃粘蛋白强烈抑制AAVP的凝血活性 .AAVP具有较好的热稳定性 ,能够忍受极端的酸碱条件 .AAVP的凝血活性不受Ca2 + 、Mg2 + 、Zn2 + 等二价阳离子的影响 .抗肿瘤活性检测表明 ,AAVP对胃癌细胞株SGC 790 1,MGC 80 3,BGC82 3及人急性白血病细胞株HL 6 0有明显的抑制作用 .AAVP对小鼠腹腔注射的半致死剂量为 15 85mg kg .     

Methylparaben induces malformations and alterations on apoptosis,oxidant–antioxidant status,ccnd1 and myca expressions in zebrafish embryos

Methylparabens (MP) are widely used as preservatives in cosmetics, pharmacy, and food industry. Although acute toxicity studies in animals indicated that parabens are not significantly toxic, the effects of chronic exposure under sublethal doses are still unknown and the number of related studies is limited. Our aim was to evaluate the effects of MP on the development of zebrafish embryos focusing on development, locomotor activity, oxidant–antioxidant status, apoptosis, and ccnd1 and myca expressions. The expressions of ccnd1 and myca were determined by RT‐PCR. Lipid peroxidation (LPO), nitric oxide (NO), and glutathione‐S‐transferase (GST) activities were determined spectrophotometrically. Apoptosis was determined using acridine orange staining. Locomotor activity was measured using touch‐evoked movement test. MP exposure increased malformations, LPO, apoptosis, ccnd1 and myca expressions, and decreased GST activities and NO levels compared with the control group. Our findings will lead to further understanding of the mechanism of MP toxicity, and merit further research.     

Diverse Brain Myeloid Expression Profiles Reveal Distinct Microglial Activation States and Aspects of Alzheimer’s Disease Not Evident in Mouse Models

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The mechanism underlying the effects of the cell surface ATP synthase on the regulation of intracellular acidification during acidosis

The F1F0 ATP synthase has recently become the focus of anti‐cancer research. It was once thought that ATP synthases were located strictly on the inner mitochondrial membrane; however, in 1994, it was found that some ATP synthases localized to the cell surface. The cell surface ATP synthases are involved in angiogenesis, lipoprotein metabolism, innate immunity, hypertension, the regulation of food intake, and other processes. Inhibitors of this synthase have been reported to be cytotoxic and to induce intracellular acidification. However, the mechanisms by which these effects are mediated and the molecular pathways that are involved remain unclear. In this study, we aimed to determine whether the inhibition of cell proliferation and the induction of cell apoptosis that are induced by inhibitors of the cell surface ATP synthase are associated with intracellular acidification and to investigate the mechanism that underlines the effects of this inhibition, particularly in an acidic tumor environment. We demonstrated that intracellular acidification contributes to the cell proliferation inhibition that is mediated by cell surface ATP synthase inhibitors, but not to the induction of apoptosis. Intracellular acidification is only one of the mechanisms of ecto‐ATP synthase‐targeted antitumor drugs. We propose that intracellular acidification in combination with the inhibition of cell surface ATP generation induce cell apoptosis after cell surface ATP synthase blocked by its inhibitors. A better understanding of the mechanisms activated by ecto‐ATP synthase‐targeted cancer therapies may facilitate the development of potent anti‐tumor therapies, which target this enzyme and do not exhibit clinical limitations. J. Cell. Biochem. 114: 1695–1703, 2013. © 2013 Wiley Periodicals, Inc.     

Insights into the evolution of lanthipeptide biosynthesis

Lanthipeptides are a group of posttranslationally modified peptide natural products that contain multiple thioether crosslinks. These crosslinks are formed by dehydration of Ser/Thr residues followed by addition of the thiols of Cys residues to the resulting dehydroamino acids. At least four different pathways to these polycyclic natural products have evolved, reflecting the high efficiency and evolvability of a posttranslational modification route to generate conformationally constrained peptides. The wealth of genomic information that has been made available in recent years has started to provide insights into how these remarkable pathways and their posttranslational modification machineries may have evolved. In this review, we discuss a model for the evolution of the lanthipeptide biosynthetic enzymes that has recently been developed based on the currently available data.     

HMPAS: Human Membrane Protein Analysis System

Background

Membrane proteins perform essential roles in diverse cellular functions and are regarded as major pharmaceutical targets. The significance of membrane proteins has led to the developing dozens of resources related with membrane proteins. However, most of these resources are built for specific well-known membrane protein groups, making it difficult to find common and specific features of various membrane protein groups.

Methods

We collected human membrane proteins from the dispersed resources and predicted novel membrane protein candidates by using ortholog information and our membrane protein classifiers. The membrane proteins were classified according to the type of interaction with the membrane, subcellular localization, and molecular function. We also made new feature dataset to characterize the membrane proteins in various aspects including membrane protein topology, domain, biological process, disease, and drug. Moreover, protein structure and ICD-10-CM based integrated disease and drug information was newly included. To analyze the comprehensive information of membrane proteins, we implemented analysis tools to identify novel sequence and functional features of the classified membrane protein groups and to extract features from protein sequences.

Results

We constructed HMPAS with 28,509 collected known membrane proteins and 8,076 newly predicted candidates. This system provides integrated information of human membrane proteins individually and in groups organized by 45 subcellular locations and 1,401 molecular functions. As a case study, we identified associations between the membrane proteins and diseases and present that membrane proteins are promising targets for diseases related with nervous system and circulatory system. A web-based interface of this system was constructed to facilitate researchers not only to retrieve organized information of individual proteins but also to use the tools to analyze the membrane proteins.

Conclusions

HMPAS provides comprehensive information about human membrane proteins including specific features of certain membrane protein groups. In this system, user can acquire the information of individual proteins and specified groups focused on their conserved sequence features, involved cellular processes, and diseases. HMPAS may contribute as a valuable resource for the inference of novel cellular mechanisms and pharmaceutical targets associated with the human membrane proteins. HMPAS is freely available at http://fcode.kaist.ac.kr/hmpas.