高压静电场对雏鸡细胞免疫功能及其调节的影响

应用细胞培养技术和四甲基偶氮唑盐（MTT）测定法对高压静电场照射雏鸡血液和免疫器官的T细胞对刀豆蛋白（ConA）的增殖反应及其白细胞介素-2（IL-2）诱生活性的动态变化进行了较全面系统的研究.结果发现,高压正静电场照射雏鸡血液和免疫器官的T细胞增殖功能及其IL-2诱生活性均明显高于高压负静电场照射雏鸡和对照雏鸡;而高压负静电场照射雏鸡血液和免疫器官的上述各项被检指标均不同程度的低于对照雏鸡.表明高压正静电场照射对雏鸡血液和免疫器官的细胞免疫功能及其调节具有促进作用,而高压负静电场照射可使雏鸡血液和免疫器官的细胞免疫功能及其调节减弱或降低.     

高压静电场对草莓采后一些生理指标的影响

草莓果实经-50和-100 kV*m-1高压静电场处理后,呼吸速率受到明显抑制,果实中可溶性固形物含量较高,多聚半乳糖醛酸酶和羧甲基纤维素酶活性降低,果实硬度下降缓慢.     

高压静电场影响小白鼠体重增长的研究

四种高压静电场影响小白鼠生长的试验结果表明,高压正静电场作用下生长过程明显加快,体重增加。     

高压静电场对黄瓜种子萌发期生理指标的影响

采用20 kV/cm高压静电场强度,分别以20、30、40 s处理黄瓜种子,结果表明:处理20 s的黄瓜种子在萌发期间各项生理指标均显著高于对照组。随处理时间延长,高压静电场对黄瓜种子萌发的促进作用减弱甚至产生抑制作用。     

十二烷基硫酸钠对高压静电场对酶作用的影响

研究了十二烷基硫酸钠(SDS)对高压静电场对酶作用的影响。结果表明:在强度为3×103V/cm的电场作用下,十二烷基硫酸钠使过氧化氢酶对高压静电场的作用变得更加敏感。低浓度的十二烷基硫酸钠中,过氧化氢酶在高压静电场的作用下活力升高;0.04mmol/L～0.12mmol/L的十二烷基硫酸钠中,酶活力在高压静电场作用下先升高后下降;高于0.40mmol/L,则酶活力单调下降。十二烷基硫酸钠对高压静电场中的过氧化氢酶具有一定的保护作用。     

高压静电场(HVEF)对人参生长及土壤化学性质的影响

对人参植株施以一定强度的高压静电场(HVEF),在一个生长季节里,使人参增产12.6%.皂甙含量提高2.31%,人参中无机元素的含量明显提高,土壤中无机元素含量相应下降.这表明人工施加的正高压静电场可促进人参对土壤中无机无素的吸收及人参产量和质量的提高.     

mirRNA-17-5p抑制物对骨肉瘤细胞系SOSP_9607增殖和凋亡的影响

目的:探讨miR-17-5p抑制物对于骨肉瘤细胞系SOSP_9607细胞增殖和凋亡的影响.方法:四甲基偶氮唑蓝(MTT)法测定细胞增殖,进一步计算抑制率,流式细胞仪测定细胞凋亡.将SOSP_9607细胞分为对照组和实验组,对照组分为阴性对照和正常细胞对照组.实验组采用miR-17-5p抑制物(hsa-miR-17-5p inhibitors)抑制SOSP_9607细胞内miR-17-5p的活性.结果:与对照组相比,实验组显著抑制SOSP_9607细胞的增殖,有明显的剂量依赖性(P<0.01).随着浓度从50 nmol/L逐渐增加至200 nmol/L,抑制率逐渐增高(P<0.01).实验组凋亡率(9.6±1.8)%与阴性对照组凋亡率(3.5±0.4)%相比明显增高(P<0.01).结论:miR-17-5p抑制物通过抑制SOSP_9607细胞中miR-17-5p的活性对SOSP_9607细胞的增殖和凋亡发挥重要作用.     

糖鞘脂GM1调控生长密度相关的乳腺细胞体外增殖抑制

细胞在体内增殖受到制约,以确保器官的正常大小和组织稳态的维持,体外培养的细胞也存在接触抑制生长现象.分布于细胞膜上的糖鞘脂具有调控细胞增殖的作用.本研究探讨了糖鞘脂GM1对人乳腺细胞MCF-10A、人乳腺癌细胞BT-549和SK-BR3增殖的影响.通过对细胞不同接种量研究细胞增殖的变化;利用流式细胞术检测细胞在不同密度生长时GM1的表达差异;探索细胞在不同密度生长时外源添加GM1对细胞增殖的影响;构建GM1干扰和过表达细胞并检测转染细胞株的增殖差异.结果显示,相较于常规密度,在低密度和高密度生长时,细胞增殖受到抑制,GM1表达量提高;GM1处理抑制低密度和高密度生长时细胞增殖,对常规密度生长细胞没有显著影响.在低密度和高密度生长时,GM1干扰细胞增殖能力提高,而GM1过表达细胞增殖能力下降.综上,本实验研究证实GM1抑制乳腺细胞MCF-10A、乳腺癌细胞BT-549和SKBR-3在体外低密度和高密度生长时的细胞增殖,为研究GM1抑制细胞增殖分子机理提供了工作基础.     

高压静电场对离子溶液中过氧化氢酶的作用研究

研究了 KBr、磷酸缓冲液、Na Cl对高压静电场对过氧化氢酶作用的影响。结果表明 :浓度在 0 .0 2 m mol/L～ 0 .0 5 m mol/L的低浓度的无机离子对高压静电场对过氧化氢酶的作用影响很小。浓度在 0 .1mmol/L～0 .4 0 m mol/L的无机离子对高压静电压对过氧化氢酶的活力影响较大 ,过氧化氢酶在 3× 10 3V /cm的电场作用下活力只会升高。而对照出现先下降后上升的现象。浓度高于 0 .80 m mol/L时 ,无机离子可以保护过氧化氢酶不受高压静电场的影响。无机离子的这种效应可能是无机离子在高压静电场的作用下 ,产生反抗电场降低了高压静电场的强度所致。     

高压静电场对植物生物学效应的研究进展

本文系统阐述了高压静电场对植物的生物学效应。主要包括高压静电场对种子和植株的影响,对愈伤组织及果蔬保鲜的影响也进行了探讨。然后着重从酶活性、膜通透性、胞内水分子状态、遗传变异、物质代谢五个方面分析了高压静电场对植物影响的机理。同时对从机理方面研究高压静电场的生物学效应及高压静电场的应用进行了讨论和展望。     

Cell separation with horizontal cell electrophoresis under near-isopycnic conditions on a “density cushion”

This report describes an improvement made to the horizontal cell electrophoresis methodology. It involves using two liquid layers differing in density to produce an interface described as a "density cushion". The electrophoretic system that employed an anti-convective porous matrix to separate red blood cells (RBC) and charged dyes effectively was found to be unsuitable for some other mammalian cells. The "density cushion" method was found to be more versatile and applicable to studies on the separation of a variety of cell types. The experiments described show the differences between the electrophoretic mobilities of a human eosinophilic leukaemia cell line (Eol-1) and RBC, both with and without the modification of the cell surface properties.     

Cell electrophoresis — a method for cell separation and research into cell surface properties

In this paper, we discuss the application of various methods of cell electrophoresis in research into cell surface properties (analytical methods), and the separation of uniform cell subpopulations from cell mixtures (preparative methods). The emphasis is on the prospects of the development of simplified and versatile methodologies, i.e. microcapillary cell electrophoresis and horizontal cell electrophoresis under near-isopycnic conditions. New perspectives are considered on the use of analytical and preparative cell electrophoresis in research on cell differentiation, neoplastic transformation, cell-cell interactions and the biology of stem cells. Paper authored by participants of the international conference: XXXIV Winter School of the Faculty of Biochemistry, Biophysics and Biotechnology of Jagiellonian University, Zakopane, March 7–11, 2007, “The Cell and Its Environment”. Publication cost was covered by the organisers of this meeting.     

Polarization and Migration of Hematopoietic Stem and Progenitor Cells Rely on the RhoA/ROCK I Pathway and an Active Reorganization of the Microtubule Network

Understanding the physiological migration of hematopoietic progenitors is important, not only for basic stem cell research, but also in view of their therapeutic relevance. Here, we investigated the role of the Rho kinase pathway in the morphology and migration of hematopoietic progenitors using an ex vivo co-culture consisting of human primary CD34⁺ progenitors and mesenchymal stromal cells. The addition of the Rho kinase inhibitor Y-27632 led to the abolishment of the uropod and microvillar-like structures of hematopoietic progenitors, concomitant with a redistribution of proteins found therein (prominin-1 and ezrin). Y-27632-treated cells displayed a deficiency in migration. Time-lapse video microscopy revealed impairment of the rear pole retraction. Interestingly, the knockdown of ROCK I, but not ROCK II, using RNA interference (RNAi) was sufficient to cause the referred morphological and migrational changes. Unexpectedly, the addition of nocodazole to either Y-27632- or ROCK I RNAi-treated cells could restore their polarized morphology and migration suggesting an active role for the microtubule network in tail retraction. Finally, we could demonstrate using RNAi that RhoA, the upstream regulator of ROCK, is involved in these processes. Collectively, our data provide new insights regarding the role of RhoA/ROCK I and the microtubules in the migration of stem cells.     

Expanisns

Biochemical dissection of the “acid-growth” process of plant cell walls led to the isolation of a new class of wall loosening proteins, called expansins. These proteins affect the rheology of growing walls by permitting the microfibril-matrix network to slide, thereby enabling the wall to expand. Molecular sequence analysis suggests that expansins might have a cryptic glycosyl transferase activity, but biochemical results suggest that expansins disrupt noncovalent bonding between microfibrils and the matrix. Recent discoveries of a new expansin family and gene expression in fruit, meristerms and cotton fibers have enlarged our view of the developmental functions of this group of wall loosening proteins.     

酸性磷酸酶法检测体外培养细胞数

利用小鼠成纤维细胞系(NIH3T3)、小鼠骨髓瘤细胞系(SP2/0)、人大肠癌细胞系(LO-VO)和人白血病细胞系(K562),评价酸性磷酸酶(APA)法用于检测体外各类型细胞的增殖和杀伤作用。用直线回归分析光吸收度与每孔活细胞数的关系。结果表明,APA法能准确地反映检测的活细胞数(相关系数均>0.99)。本方法不仅能很好地检测表皮生长因子对细胞的增殖作用,也能够检测顺铂对体外细胞的杀伤作用。结果表明APA法简单、灵敏,可以用于上皮和间质等贴壁和悬浮生长的细胞计数。     

An overview of the KIN1/PAR-1/MARK kinase family

Members of the KIN1/PAR-1/MARK kinase family are conserved from yeast to humans and share a similar primary structural organization. Several kinases of this family appear to be at the crossroads of various biological functions including cell polarity, cell cycle control, intracellular signalisation, microtubules stability and protein stability. Here we present an overview of known roles of KIN1/PAR-1/MARK kinases including pEg3 a newly identified member which is regulated during the cell cycle and is a potential regulator of the cell cycle progression. Some common modes of action can be deciphered for this protein kinase family.     

犬皮肤成纤维细胞的分离、培养及鉴定

目的探索和建立适用于犬皮肤成纤维细胞的体外分离、培养及鉴定的技术方法。方法采用组织贴块培养法和胰蛋白酶、胶原酶Ⅰ联合消化法对犬皮肤成纤维细胞进行体外培养、传代。并对所培养的细胞进行倒置显微镜观察和苏木素-伊红染色,观察成纤维细胞形态,并对培养细胞行波形蛋白免疫荧光染色。结果倒置相差显微镜下可见长梭形细胞生长,苏木素-伊红染色可见细胞呈漩涡状、平行排列,第5代细胞免疫荧光检测波形蛋白(vimentin)表达阳性。结论建立了高效快速分离和稳定培养成纤维细胞的方法,为诱导犬心房纤维化提供了充足的种子细胞。     

miR-125a-5p转染对肝癌细胞增殖、侵袭、迁移的影响及相关机制研究

摘要 目的：探究miR-125a-5p转染对肝癌细胞增殖、侵袭、迁移的影响及相关机制。方法：将肝癌细胞分为对照组、下调组和上调组,并通过细胞转染建立稳定转染的下调组和上调组。MMT法检测细胞增殖能力,流式细胞仪检测细胞凋亡能力,Transwell小室实验检测细胞侵袭能力,细胞划痕实验检测细胞迁移能力,Western blot法检测P13K/Akt通路中AKT、Bax、Bcl-2、P13K、P-AKT蛋白表达量。结果：与上调组相比,下调组24、48、72 h细胞增殖率,细胞侵袭、迁移细胞数,AKT、Bcl-2、P13K、P-AKT蛋白表达量显著降低,具有统计学差异（29.67±9.87 vs 17.34±5.71,t=5.192,P＜0.05、34.75±11.56 vs 15.17±5.04,t=7.365,P＜0.05、38.48±12.81 vs 12.51 ±4.13,t=9.153,P＜0.05,72.53±24.17 vs 36.28±12.07,t=6.365,P＜0.05、86.51±28.75 vs 46.28±15.32,t=5.858,P＜0.05,1.26±0.41 vs 0.81±0.26,t=4.397,P＜0.05、1.35±0.44 vs 0.76±0.24,t=5.584,P＜0.05、1.48±0.46 vs 0.79±0.26,t=6.194,P＜0.05、1.22±0.39 vs 0.73±0.24,t=5.584,P＜0.05）;与上调组相比,下调组24、48、72h细胞凋亡率,Bax蛋白表达量显著升高,具有统计学差异（17.62±5.84 vs 29.31±9.75,t=4.879,P＜0.05、14.97±4.65 vs 34.19±11.36,t=7.427,P＜0.05、11.26±3.74 vs 38.62±12.86,t=9.690,P＜0.05,0.75±0.24 vs 1.33±0.43,t=5.587,P＜0.05）。结论：下调miR-125a-5p的表达,可通过作用于P13K/Akt通路,调控AKT、Bax、Bcl-2、P13K、P-AKT蛋白表达量,进而起到抑制肝癌细胞增殖、促进肝癌细胞凋亡以及抑制肝癌细胞的侵袭、迁移能力。     

The influence of cell volume changes on tumour cell proliferation

Ion channels and cell volume control participate in a wide variety of cellular functions, including cell proliferation. According to the pump-leak model or the double Donnan system, the cell volume is constant in physiological medium so long as the cell metabolism and the Na-K pump are not inhibited and the passive Na⁺ permeability is not dramatically increased. At short term, this model has been supported by a large number of experiments made on different cell types. However, at long term, it may be insufficient to describe the volume control because it does not take into account the fact that cells possess a large number of membrane transporters and interconnected volume regulatory mechanisms. In this review, we present recent results indicating that, in physiological conditions, ion channels may have important roles in cell volume control. Furthermore, we emphasize that cell proliferation and volume are phenomenologically correlated. On the basis of the macromolecular crowding theory, the possibility that the cell osmolyte and water content mediates this correlation is discussed.Abbreviations 4-AP 4-aminopyridine - NPPB 5-nitro-2-(3-phenylpropylamino)benzoic acid - TEA tetraethylammonium - TOR target of rapamycin Presented at the Biophysical Society Meeting on Ion channels—from structure to desease held in May 2003, Rennes, France     

The plant cell body: a cytoskeletal tool for cellular development and morphogenesis

Summary Certain aspects of cellular behaviour in relation to growth and development of plants can be understood in terms of the cell body concept proposed by Daniel Mazia in 1993. During the interphase of the mitotic cell cycle, the plant cell body is held to consist of a nucleus and a perinuclear microtubule-organizing centre from which microtubules radiate into the cytoplasm. During mitosis and cytokinesis in meristematic cells, and also during the period of growth in post-mitotic cells immediately beyond the meristem, the plant cell body undergoes various characteristic morphological transformations, many of which are proposed as being related to changing structural connections with the actin-based component of the cytoskeleton and with specialized, plasma-membrane-associated sites at the cell periphery. In post-mitotic cells, these transformations of the plant cell body coincide with, and probably provide conditions for, the various pathways of development which such cells follow. They are also responsible, for the acquisition of new cellular polarities. Events in which the plant cell body participates include the formation of a mitotic spindle, phragmoplast, and new cell division wall, the rearrangement of a diffuse type of cell wall growth into tip growth (as occurs, e.g., during the initiation and subsequent development of root hairs), and the growth and division that occurs in reactivated vacuolate cells. If more evidence can be marshalled in support of the existence and properties of the plant cell body, then this concept could prove useful in interpreting the cytological bases of a range of developmental events in plants.Abbreviations CMT cortical microtubule - EMT endoplasmic microtubule - ER endoplasmic reticulum - MF microfilament - MT microtubule - MTOC microtubule-organizing centre - PPB preprophase band (of microtubules) - QC quiescent centre - VSC vesicle supply centre