其它药剂

891680肌醇磷脂在神经信息传递中的作用仁中〕/李俊凤…了生物化学与生物物理进展。一1988,15(5)。一354tw358 本文概括了近年来肌醇磷脂的研究状况,介绍了肌醇磷脂的代谢及其代谢产物     

肌醇磷脂在神经信息传递中的作用

本文概括了近年来肌醇磷脂的研究状况,着重介绍了肌醇磷脂的代谢及其代谢产物(IP₃)和甘油二脂(DG)在信息传递中的作用,阐述了肌醇磷脂与神经信息跨突触传递的关系。     

α-核突触蛋白基因突变小鼠脑组织中内源性代谢产物的变化

目的:明确α-核突触蛋白与帕金森病的病理生理相关性及其临床意义。方法:采用相色谱-质谱联用(UPLC-MS)检测野生型小鼠和基因突变型小鼠脑组织中内源性代谢性产物,通过mzcloud法对小鼠脑组织中内源性代谢物质进行鉴定,将相应数据进行主成分分析(PCA)和聚类分析,分析其相关差异表达代谢物,并构建通路图和互作网络图。结果:(1)基于LC/MS法的代谢组分析结果显示两组间差异代谢物以氨基酸类及磷脂类等为主,包括β-丙氨酰-L-组氨酸、L-精氨酸、L-组氨酸、L-亮氨酸、L-苯丙氨酸、L-缬氨酸、L-天门冬氨酸、L-丙氨酸、磷脂酰胆碱等;(2)构建的代谢通路主要涉及酮体的合成和降解、牛磺酸和亚牛磺酸代谢、丙氨酸,天冬氨酸和谷氨酸代谢、精氨酸和脯氨酸代谢、组氨酸代谢、苯丙氨酸代谢、缬氨酸,亮氨酸和异亮氨酸的生物合成、甘油磷脂代谢等,从中发现18个具有标志性的代谢成分。结论:α-核突触蛋白基因突变后,酮体的合成和降解、牛磺酸和亚牛磺酸代谢、丙氨酸,天冬氨酸和谷氨酸代谢、精氨酸和脯氨酸代谢、组氨酸代谢、苯丙氨酸代谢、缬氨酸,亮氨酸和异亮氨酸的生物合成、甘油磷脂代谢等代谢通路发生了变化,涉及β-丙氨酰-L-组氨酸、L-精氨酸、L-组氨酸、L-亮氨酸、L-苯丙氨酸、L-缬氨酸、L-天门冬氨酸、L-丙氨酸、磷脂酰胆碱等的生物学标志性代谢产物变化。     

LC-MS分析CmSnf1基因过表达对蛹虫草代谢组的影响

Sucrose-nonfermenting1(SNF1)蛋白激酶调节大量基因的转录,改变代谢酶的活性,并控制各种营养反应性细胞发育过程。本研究通过LC-MS非靶向代谢组学技术比较蛹虫草Cordyceps militaris野生型菌株Cm01和CmSnf1基因过表达菌株菌丝体的化学成分,从整体代谢物水平阐明CmSnf1基因过表达对蛹虫草代谢产物积累的影响。研究表明：CmSnf1基因过表达后,在LC-MS正负离子模式下检测出547种差异代谢物,同野生型菌株相比,220种产物上调和327种下调。尤其显著的是黄酮类物质2-香叶基-3,4,2′,4′-四羟基二氢查耳酮上调了140.55倍,甘油磷脂代谢中的磷脂酰丝氨酸(PS)下调了47.53倍。差异代谢产物参与甘油脂代谢、氨基酸生物合成和降解、半乳糖代谢、丙酮酸和酮类化合物代谢等多种途径。CmSnf1过表达菌株与野生型相比在酮类化合物代谢上具有优势,推测CmSnf1基因在蛹虫草药用功效中发挥着重要的作用。     

代谢组学在肥胖症中的研究进展

肥胖症病因复杂,其发病机制目前尚未完全明确。代谢组学可以从分子水平对代谢途径中的终端产物进行研究,更系统全面地揭示肥胖症的发病机制。文章总结了与肥胖相关的糖、脂、氨基酸、磷脂类及肠道菌群代谢途径及其代谢标志物的变化,以期为肥胖症的临床治疗提供参考。     

细菌溶血磷脂的生物合成及生物学功能

溶血磷脂(lysophospholipids, LPLs)是细胞膜中的一类脂质代谢中间产物，主要由磷脂分子被水解后生成。LPL的生物学功能与其前体磷脂有明显的区别。在真核细胞中，LPL是一种参与多种胞内生物信号调控的重要活性分子，但在细菌中，LPL的生物学功能还未被充分揭示。LPL通常是细菌细胞膜中的次要组分，在环境压力条件下其含量可显著升高。除了参与细胞膜磷脂代谢，LPL被认为在细菌环境适应性及致病性中发挥重要作用。其在细胞膜中的累积可以显著提高细菌在环境压力下的存活及增殖效率，同时还是细菌感染过程中重要的信号分子。近期有研究表明，LPL可能是细菌新发现的潜在毒力因子。本文因此将结合最新研究数据，对不同种类LPL的从头合成通路以及LPL在细菌抵御环境压力和细菌-宿主互作等方面所发挥的生物学功能进行综述，为对细菌致病机制和防治细菌感染的相关研究提供新的思路和参考借鉴。     

溶血磷脂酸--一种具有多种生物学功能的磷脂信号分子

溶血磷脂酸(Lysophosphatidic acid,LPA)是迄今发现的一种最小、结构最简单的磷脂,它是真核细胞磷脂生物合成早期阶段的关键性前体,甘油磷脂代谢的中间产物。60年代初,Vogt等人在实验中观察到,LPA能够引起免离体肠平滑肌收缩。这一现象使人们认识到LPA不仅仅是生物膜的组成成分可能还具有某些生物学功能。随后越来越多的研究表明:LPA作为一种细胞间的磷脂信使,可以激活G蛋白偶联受体,引起生长激素样作用,从而产生广泛的生物学效应。LPA对细胞的生长、增殖、分化及细胞内信息传递产生多种影响,在维持机体正常的生理功能,参与各种病理过程的发     

佛波酯诱导一种新的磷脂酶D酶解产物的生成

在人肺癌表面细胞株A－549中检测到佛波酯诱导的丁醇化鞘脂分子的产生。用[^3H]－丝氨酸标记细胞,其放射性在磷脂酰胆碱、磷脂酰丝氨酸、磷脂酰乙醇胺极性头部的分布很容易被检测到,而在磷脂酸及其直接代谢衍生物中并不存在,提示这种磷脂酶D的酶解产物来源于鞘脂分子的水解,而不同于以甘油磷脂为底物的磷脂酶D的酶解产物。蛋白激酶C的抑制剂或通过佛波酯长时间处理下调细胞内蛋白激酶C水平,可抑制佛波酯诱导的丁酯化鞘脂分子的产生,表明导致这种磷脂酶D的活化需要蛋白激酶C的参与。     

磷脂酰胆碱对酒精性肝病保护作用的研究进展

酒精性肝病已逐渐成为第二大肝脏疾病,威胁着人类的健康。乙醇引发肝损伤的机制主要包括其代谢产物乙醛对肝细胞造成的毒性作用、自由基损伤及对肝脏线粒体产生的毒性作用等。已证实,磷脂酰胆碱对酒精肝损伤具有明显的保护作用。简要介绍了酒精肝病机制及磷脂酰胆碱对酒精性肝损伤的保护作用研究进展,以期为治疗酒精性肝病提供帮助。     

磷脂酰肌醇 -3 激酶不直接调控PC12 细胞的分泌

磷脂酰肌醇-3激酶(PI3K)是磷脂酰肌醇代谢过程中一种重要的酶,通过其代谢产物参与了对多种细胞生理活动的调节,如囊泡运输、细胞骨架重组、细胞存活、吞噬作用、细胞凋亡等.为研究其对细胞分泌功能的作用,使用磷脂酰肌醇-3激酶家族的特异性抑制剂渥曼青霉素(wortmannin)阻断磷脂酰肌醇-3激酶的活性,以EGFP-2xFYVE融合蛋白与磷脂酰肌醇-3-磷酸(PtdIns-3-P)的结合为指征,使用荧光显微成像技术检测渥曼青霉素对磷脂酰肌醇-3激酶的抑制作用,采用膜片钳膜电容测量方法及光解钙离子释放技术检测渥曼青霉素对PC12细胞分泌功能的影响.实验结果表明,wortmannin阻断了磷脂酰肌醇-3激酶的活性,抑制了磷脂酰肌醇-3-磷酸(PtdIns-3-P)的产生,并使FYVE与PtdIns-3-P解离,但渥曼青霉素处理之前和处理30 min后的PC12细胞分泌反应的幅度、动力学特性和分泌的钙依赖性均无显著差异,表明磷脂酰肌醇-3激酶对PC12细胞的分泌无显著的直接影响.     

Plant cell systems

Our present view of the structure of higher plant cell systems arising on the basis of electron, fluorescent, and confocal microscopy and also video movies of living cells under confocal microscope is presented. The role of the partition (conducting) system in the arrangement of the whole plant cell systems, their development, breakdown, and renewal is demonstrated. The phylogenetic origination of the partition net and its primary role in the ontogenetic development of the cell systems are considered in the context of the theory of endosymbiogenesis. The data concerning growth limits and a diversity of the higher plant cell system organization are compared. The specific features of the cell systems of prokaryotes, autotrophic and heterotrophic eukaryotes, and also of their evolution are discussed.     

Exploitation of plant cells for the production of natural compounds

A four-step strategy is presented which allows the establishment of plant cell cultures producing high yields of secondary plant products. The application of suitable methods (radioimmunoassay, fluorescence screening) for the selection of overproducing differentiated plants and cell colonies is stressed. By precursor feeding and hormone application, plant cell cultures can greatly be influenced in their production behavior. A highly sensitive, selective regulatory mechanism for the uptake and storage of alkaloids in Catharanthus vacuoles is demonstrated. Overproducing variant cell strains are so far the most promising tool for the future biotechnological application of the plant cell culture method.     

Plant pathogens as a source of diverse enzymes for lignocellulose digestion

The plant cell wall is a major barrier that many plant pathogens must surmount for successful invasion of their plant hosts. Full genome sequencing of a number of plant pathogens has revealed often large, complex, and redundant enzyme systems for degradation of plant cell walls. Recent surveys have noted that plant pathogenic fungi are highly competent producers of lignocellulolytic enzymes, and their enzyme activity patterns reflect host specificity. We propose that plant pathogens may contribute to biofuel production as diverse sources of accessory enzymes for more efficient conversion of lignocellulose into fermentable sugars.     

Cell cycle activation by plant parasitic nematodes

Sedentary nematodes are important pests of crop plants. They are biotrophic parasites that can induce the (re)differentiation of either differentiated or undifferentiated plant cells into specialized feeding cells. This (re)differentiation includes the reactivation of the cell cycle in specific plant cells finally resulting in a transfer cell-like feeding site. For growth and development the nematodes fully depend on these cells. The mechanisms underlying the ability of these nematodes to manipulate a plant for its own benefit are unknown. Nematode secretions are thought to play a key role both in plant penetration and feeding cell induction. Research on plant-nematode interactions is hampered by the minute size of cyst and root knot nematodes, their obligatory biotrophic nature and their relatively long life cycle. Recently, insights into cell cycle control in Arabidopsis thaliana in combination with reporter gene technologies showed the differential activation of cell cycle gene promoters upon infection with cyst or root knot nematodes. In this review, we integrate the current views of plant cell fate manipulation by these sedentary nematodes and made an inventory of possible links between cell cycle activation and local, nematode-induced changes in auxin levels.     

Plant cell culture technology in the cosmetics and food industries: current state and future trends

The production of drugs, cosmetics, and food which are derived from plant cell and tissue cultures has a long tradition. The emerging trend of manufacturing cosmetics and food products in a natural and sustainable manner has brought a new wave in plant cell culture technology over the past 10 years. More than 50 products based on extracts from plant cell cultures have made their way into the cosmetics industry during this time, whereby the majority is produced with plant cell suspension cultures. In addition, the first plant cell culture-based food supplement ingredients, such as Echigena Plus and Teoside 10, are now produced at production scale. In this mini review, we discuss the reasons for and the characteristics as well as the challenges of plant cell culture-based productions for the cosmetics and food industries. It focuses on the current state of the art in this field. In addition, two examples of the latest developments in plant cell culture-based food production are presented, that is, superfood which boosts health and food that can be produced in the lab or at home.

     

动植物细胞或组织生物反应器悬浮培养过程中的通气方式

通气在动植物细胞或组织生物反应器培养过程中起着至关重要的作用,而同时通气过程所产生的机械损伤力亦可对细胞造成直接的伤害,因此,通气方式是动植物细胞或组织生物反应器培养过程设计与工程放大的关键技术之一。本文综述了动植物细胞或组织生物反应器悬浮培养过程中三种主要通气(异养培养时又称供氧)方式的结构特点,及其对气液传质、生物量、代谢产物量和细胞损伤的影响,以及改进的新型通气方式和几种通气方式的融合并用。     

Expansive growth of plant cell walls.

The enlargement of plant cell walls is a key determinant of plant morphogenesis. Current models of the cell wall are reviewed with respect to their ability to account for the mechanism of cell wall enlargement. The concept of primary and secondary wall loosening agents is presented, and the possible roles of expansins, xyloglucan endotransglycosylase, endo-1,4-beta-D-glucanase, and wall synthesis in the process of cell wall enlargement are reviewed and critically evaluated. Experimental results indicate that cell wall enlargement may be regulated at many levels.     

Pathogen-Induced Plant Proteins (Review)

Pathogen-induced plant proteins are classified according to their functional characteristics: involvement in plant cell signaling; inhibition of enzymes excreted by pathogens; stabilization of plant cell walls; ability to trigger apoptosis; enzymatic activity producing lysis of cell walls of pathogenic fungi and bacteria; enzymatic activity in metabolic pathways of phenylpropanoid and terpenoid phytoalexins; and ability to affect pathogens directly by disturbing the function of their cell membranes or by deactivating their ribosomes. Examples of transgenic plants with increased immunity against pathogens are also provided.     

Nep1-like proteins from plant pathogens: recruitment and diversification of the NPP1 domain across taxa

An emerging group of proteins found in many plant pathogens are related to their ability to cause plant cell death. These proteins may be identified by the presence of a common NPP1 (necrosis-inducing Phytophthora protein) domain, and have collectively been named NLPs (Nep1-like proteins). The NLPs are distinguished by their wide distribution across taxa and their broad spectrum of activity against dicotyledonous plants. The function of NLPs is not known but there is strong evidence that they may act as positive virulence factors, accelerating disease and pathogen growth in plant hosts. Interest in NLPs is gaining momentum as more members of this protein family are discovered in more species of plant pathogens.     

Insights into the G1/S transition in plants

The G1/S transition generally represents the principal point of commitment to cell division. Many of the components of the cell cycle core machinery regulating the G1/S transition in plants have been recently identified. Although plant regulators of the G1/S transition display structural and biochemical homologies with their animal counterparts, their functions in integrating environmental stimuli and the developmental program within cell cycle progression are often plant-specific. In this review, recent progress in understanding the role of plant G1/S transition regulators is presented. Emerging evidence concerning the mechanisms of G1/S control in response to factors triggering the cell cycle and the integration of these mechanisms with plant development is also discussed.