Nerve regeneration factor promotes nerve regeneration in rat

Nerve regeneration factor (NRF) extracted from an oral liquid of traditional Chinese medicine, as a nerve growth decoction has been reported by previous studies to exert effects of promoting nerve growth and preventing neuron apoptosis. For new insights into the function of NRF on primary cultured neurons, we investigated the neurite outgrowth in cultured rat dorsal root ganglion (DRG) explant treated with NRF by immunofluorescence and the gene and protein expressions of neurofilament-H(NF-H) and growth associated protein 43 (GAP43) in the cultured rat DRG neurons by real-time quantitative RT-PCR and Western blotting, respectively. In addition, we used a rat model of sciatic nerve crush to evaluate the effect of NRF on regeneration of injured sciatic nerve by a combination of walk track analysis, electrophysiological and histological assessments. The in vitro experiments indicated that NRF promoted the neurite growth of DRGs and the expression of NF-H and GAP43 at mRNA and protein levels in DRG neurons, and in vivo experiments showed that NRF improved peripheral nerve regeneration and functional recovery.     

枣仁皂甙A对海马神经细胞的影响

在实验室建立了体外培养新生大鼠海马神经细胞方法，观察和研究枣仁皂甙A（JuA）对海马神经细胞生长的影响，用免疫组化和免疫荧光法鉴定神经细胞，M1rr检测神经细胞存活率。试验结果表明，培养细胞为高纯度的海马神经细胞，JuA组的海马神经细胞存活率明显高于对照组（p〈0．01），且呈现一定剂量相关性，提示JuA对体外培养的新生大鼠海马神经细胞的生长有一定的促进作用     

怀牛膝毛状根诱导及培养体系的建立

以牛膝叶片为外植体,研究了不同发根农杆菌、培养基、乙酰丁香酮(AS)对毛状根诱导率及其生长的影响.结果表明,发根农杆菌不同菌种对牛膝叶片转化率有显著影响,3个供试菌种中ATCC15834菌株诱导率最高;在1/2MS无激素固体培养基上毛状根的诱导率及生长状况均优于MS培养基;100μmol·L-1 AS可以有效提高毛状根诱导率.毛状根从叶片形态学下端中脉切口处形成的愈伤组织上产生,能在无外源激素的培养基上自主生长.PCR扩增结果显示发根农杆菌Ri质粒的rolB基因已在牛膝毛状根基因组中插入、整合并得到表达.建立了牛膝毛状根诱导培养体系,为利用毛状根大规模生产药用成分奠定了基础.     

苦丁茶对MCF-7人乳腺癌细胞的体外抗癌效果

对市售的苦丁茶进行MCF-7人乳腺癌细胞体外抗癌效果和体内抗转移效果评价.通过MTT实验、DAPI荧光染色分析和RT-PCR分析说明其体外抗癌效果.200μg/mL苦丁茶(81%抑制率)水提物表现出对MCF-7人乳腺癌细胞较强的生长抑制效果.200μg/mL比100和50μg/mL苦丁茶水提物具有更强的细胞诱导凋亡效果,Bax,caspase-3和caspase-9的mRNA表达得到增强,Bcl-2表达减弱.苦丁茶水提物处理后炎症相关因子NF-κB,iNOS和COX-2表达减弱,展示了苦丁茶的抗炎特性.由此得出,一定质量浓度的苦丁茶具有良好的抗癌预防效果.     

Nogo-A is a myelin-associated neurite outgrowth inhibitor and an antigen for monoclonal antibody IN-1

The capacity of the adult brain and spinal cord to repair lesions by axonal regeneration or compensatory fibre growth is extremely limited. A monoclonal antibody (IN-1) raised against NI-220/250, a myelin protein that is a potent inhibitor of neurite growth, promoted axonal regeneration and compensatory plasticity following lesions of the central nervous system (CNS) in adult rats. Here we report the cloning of nogo A, the rat complementary DNA encoding NI-220/250. The nogo gene encodes at least three major protein products (Nogo-A, -B and -C). Recombinant Nogo-A is recognized by monoclonal antibody IN-1, and it inhibits neurite outgrowth from dorsal root ganglia and spreading of 3T3 fibroblasts in an IN-1-sensitive manner. Antibodies against Nogo-A stain CNS myelin and oligodendrocytes and allow dorsal root ganglion neurites to grow on CNS myelin and into optic nerve explants. These data show that Nogo-A is a potent inhibitor of neurite growth and an IN-1 antigen produced by oligodendrocytes, and may allow the generation of new reagents to enhance CNS regeneration and plasticity.     

合欢花水提物对大鼠脑胶质瘤C6细胞株的增殖抑制与凋亡诱导作用

采用MTT法检测合欢花水提物对C6细胞增殖活力的影响,流式细胞术检测该水提物对C6细胞的诱导凋亡作用.结果表明:合欢花水提物能抑制C6细胞的增殖,且具有剂量和时间依赖性,其在24 h、48 h、72 h时对C6细胞的半数抑制率(LD50)分别为:305 μg/mL、50 μg/mL、15 μg/mL.流式细胞术结果显示:200 tμg/mL、300μg/mL合欢花水提物均可诱导C6细胞发生早期凋亡,与对照组细胞相比,早期凋亡率分别由对照组的0.7％增加到了4.3％、14.3％.提示合欢花水提物抑制C6细胞增殖机理与诱导细胞凋亡途径有关.     

Centrosome localization determines neuronal polarity

Neuronal polarization occurs shortly after mitosis. In neurons differentiating in vitro, axon formation follows the segregation of growth-promoting activities to only one of the multiple neurites that form after mitosis. It is unresolved whether such spatial restriction makes use of an intrinsic program, like during C. elegans embryo polarization, or is extrinsic and cue-mediated, as in migratory cells. Here we show that in hippocampal neurons in vitro, the axon consistently arises from the neurite that develops first after mitosis. Centrosomes, the Golgi apparatus and endosomes cluster together close to the area where the first neurite will form, which is in turn opposite from the plane of the last mitotic division. We show that the polarized activities of these organelles are necessary and sufficient for neuronal polarization: (1) polarized microtubule polymerization and membrane transport precedes first neurite formation, (2) neurons with more than one centrosome sprout more than one axon and (3) suppression of centrosome-mediated functions precludes polarization. We conclude that asymmetric centrosome-mediated dynamics in the early post-mitotic stage instruct neuronal polarity, implying that pre-mitotic mechanisms with a role in division orientation may in turn participate in this event.     

Effect of thrombin on the apoptosis of hippocampal neurons in vitro

Hippocampal neurons were treated by thrombin and thrombin receptor activating peptides (TRAP). Cell survival rate was decreased in a dose-dependent manner by MTT assay. The numbers of apoptotic cell and apoptotic rate of hippocampal neurons treated by different concentrations of thrombin were increased in a dose-dependent manner by terminal deoxynucleotidyl transferase (TdT) mediated dUTP-biotin nick end-labeling (TUNEL) method and Flow Cytometry. When the concentration of thrombin is 40 U/mL, TUNEL positive cells and apoptotic rate of hippocampal neurons reached peak value, were 27.3±4.0 and (29.333±4.633)%, respectively. Immunocytochemistry assay show that Bcl-2 protein expression was down-regulated and Bax protein expression was up-regulated with the concentration of thrombin increased. TRAP can mimic the effect of thrombin to induce apoptosis on hippocampal neurons. These data demonstrated that thrombin induced hippocampal neuron apoptosis in a dose-dependent manner through activating protease-activated protein-1 (PAR-1). The change in expression of Bcl-2 and Bax was related with the effect of high concentration thrombin induced apoptosis on hippocampal neurons. Foundation item: Supported by the Natural Science Foundation of Hainan Province (N30215) Biography: YANG Wen-qiong (1968-), female, Ph.D. candidate, research direction: cerebrovascular disease.     

苦楝叶乙醇浸提物对几种作物种子萌发及幼苗生长的影响

以苦楝（Melia azedarach）叶乙醇浸提物处理大豆（Glycine mac）、水稻（Oryza stativa）、小麦（Triticum aes-tivum）及玉米（Zeamays）种子,观察浸提物对几种作物种子萌发及幼苗生长的影响。结果表明,在62.5～1000μg/mL浓度范围内,浸提物对几种作物种子的萌发及幼苗生长具有一定的抑制作用,但对水稻和小麦的抑制作用较强,对玉米和大豆的抑制作用稍弱,在1000μg/mL浓度时,浸提物可完全抑制水稻和小麦种子萌发及幼苗的生长,而大豆和玉米的萌发率仍超过70%,对大豆幼苗的苗高和根长,玉米幼苗的苗高抑制作用均低于50%。     

佛甲草中细胞毒活性成分的研究

采用中压柱色谱和制备高效液相色谱法对中国传统民族药佛甲草(Sedum lineare Thunb)的甲醇提取物化学成分进行分离,从中分离得到6个化合物.首次对化合物山奈酚7-O-6″-O-丙二酸单酰-D-吡喃葡萄糖苷(1)的波谱数据进行了归属,用MTT法测试6个单体成分对人肝癌细胞株HepG2和Hep3B的抑制作用.结果显示6个化合物均对HepG2和Hep3B细胞表现出抗肿瘤活性,并且IC50值在22.6～91.5 μg/mL之间,在浓度大于100 μg/mL时也没有表现出对人正常肝细胞L－02的抑制作用.相比于黄酮类化合物1、2,苯丙酸类化合物3～6(IC50＝22.6～44.3 μg/mL)对HepG2和Hep3B细胞表现出更强的抑制作用.其中,顺式苯丙酸类化合物5对HepG2和Hep3B细胞的抑制作用最明显.其IC50值范围在22.6～28.2 μg/mL,能明显抑制人肝癌细胞的增殖,诱导其凋亡.     

苍耳子提取物对斑马鱼的发育及运动行为的毒性研究

为研究苍耳子提取物对斑马鱼胚胎发育及运动行为的影响,取受精后12/24 h斑马鱼胚胎,将胚胎分别置于不同浓度苍耳子提取物溶液中,在作用不同时间后,显微镜下统计孵化率、死亡率和心率;取受精后120 h斑马鱼胚胎,用不同浓度苍耳子提取物处理60 min后,利用行为学分析系统统计各组斑马鱼在0~10、10~20、20~30 min内行为轨迹,基于游行距离与游行时间得到游行速度,并统计转圈值。结果表明,苍耳子提取物对受精后12 h斑马鱼胚胎的发育有毒性,使斑马鱼胚胎的孵化率降低,在提取物浓度大于15μg/mL时,孵化率低于40%;0.93μg/mL苍耳子提取物可提高24 h斑马鱼胚胎的心率(P≤0.01),当提取物浓度大于7.5μg/mL时,心率显著性降低(P≤0.01);在行为学分析中发现,当苍耳子提取物浓度大于3μg/mL时,游行速度与转圈均值明显增加。研究认为,苍耳子提取物对斑马鱼胚胎发育有毒性作用,能够兴奋斑马鱼胚胎心率并增加其游行速度。     

A threshold effect of the major isoforms of NCAM on neurite outgrowth

Interactions between recognition molecules on the surface of neuronal growth cones and guidance cues present in the local cellular environment are thought to account for the growth of neurites in the highly stereospecific manner that contributes to correct target cell innervation. In vitro assays have been used to identify candidate molecular components of this system, either directly by demonstrating their ability to promote neurite outgrowth, or indirectly by the ability of specific antibodies to inhibit neurite outgrowth. The role of the neural cell adhesion molecule (NCAM) in pathway finding is not fully understood. Some immunological studies support a positive role; others do not, and it has been reported that purified NCAM does not support neurite outgrowth. We have previously shown that an arbitrary biochemical index of neurite outgrowth, the relative level of immunoreactive neurofilament protein, is increased when human and rat dorsal root ganglion neurons are cultured on monolayers of cells expressing transfected human NCAM. But, the complexity of growth precluded a simple morphological analysis and we did not determine the 'dose-response' relationship between NCAM expression and neuronal response. Here, we report on the morphology of rat cerebellar neurons cultured on monolayers of 3T3 cells transfected with complementary DNAs encoding all of the main NCAM isoforms found in cells such as astrocytes, Schwann cells and skeletal muscle. The data indicate that both transmembrane and glycosyl-phosphatidylinositol linked NCAM isoforms are potent substrates for neurite extension. A critical threshold value of NCAM expression is required for increased neurite outgrowth. Above this threshold, small increases in NCAM induce substantial increases in neurite outgrowth.     

Development of neuronal polarity: GAP-43 distinguishes axonal from dendritic growth cones

Outgrowth of distinct axonal and dendritic processes is essential for the development of the functional polarity of nerve cells. In cultures of neurons from the hippocampus, where the differential outgrowth of axons and dendrites is readily discernible, we have sought molecules that might underlie the distinct modes of elongation of these two types of processes. One particularly interesting protein is GAP-43 (also termed B-50, F1 or P-57), a neuron-specific, membrane-associated phosphoprotein whose expression is dramatically elevated during neuronal development and regeneration. GAP-43 is among the most abundant proteins in neuronal growth cones, the motile structures that form the tips of advancing neurites, but its function in neuronal growth remains unknown. Using immunofluorescence staining, we show that GAP-43 is present in axons and concentrated in axonal growth cones of hippocampal neurons in culture. Surprisingly, we could not detect GAP-43 in growing dendrites and dendritic growth cones. These results show that GAP-43 is compartmentalized in developing nerve cells and provide the first direct evidence of important molecular differences between axonal and dendritic growth cones. The sorting and selective transport of GAP-43 may give axons and axonal growth cones certain of their distinctive properties, such as the ability to grow rapidly over long distances or the manner in which they recognize and respond to cues in their environment.     

Anti-allergic effects of ethanol extracts from brown seaweeds

Ethanol extracts of brown seaweeds from Pakistan and China were isolated and compared for their antiallergenic activities. They included Sargassum tennerimum (ST) and Sargassum cervicorne (SC) from Pakistan, and Sargassum graminifolium turn (SG), Sargassum thunbergii (STH), and Laminaria japonica (LJ) from China. The ethanol extracts of these brown seaweeds were optimized at 85% (v/v) ethanol for the maximum yield of phlorotannin, an inhibitor against hyaluronidase. Total phlorotannins contained in the crude extracts were measured as 1.71% (SG), 0.74% (STH), 0.97% (LJ), 3.30% (SC), and 5.06% (ST). The 50% inhibitory concentrations (IC₅₀) of Pakistani SC and ST were 109.5 and 21 μg/ml, respectively, lower than those of Chinese SG, STH, and LJ (134, 269, and 148 μg/ml, respectively). An antiallergic drug, disodium cromoglycate (DSCG), had an IC₅₀=39 μg/ml, and a natural inhibitor of hyaluronidase, catechin, had an IC₅₀=20 μg/ml. The IC₅₀ of ST extract was found similar to that of catechin (21 vs 20 μg/ml) and lower than that of DSCG (21 vs 39 μg/ml). This suggests that ST is a potent inhibitor of hyaluronidase, indicating a promising future development of natural antiallergic medicines or functional foods.     

Basic fibroblast growth factor prevents death of lesioned cholinergic neurons in vivo

Cutting the axons of the cholinergic neurons that project to the hippocampal formation results in death of most of these cells. Previous studies have shown that administration of nerve growth factor before or at the same time as the lesion will prevent this cell death. Here we demonstrate that basic fibroblast growth factor (FGF) administered into the brain reduces the death of cholinergic neurons in the medial septum and diagonal band of Broca after transection of their axons, in both young adult and aged rats. Moreover, FGF can partially protect against death of cholinergic neurons even when administered two days after axonal transection. These results indicate a possible function for FGF in the normal support of basal forebrain cholinergic neurons, but its range of activity could be wider, for FGF also supports noncholinergic neurons in vitro, it is localized in many of the central nervous system neurons, and it is found in relatively high concentrations in the brain.     

Presenilin is required for proper morphology and function of neurons in C. elegans

Mutations in the human presenilin genes cause the most frequent and aggressive forms of familial Alzheimer's disease (FAD). Here we show that in addition to its role in cell fate decisions in non-neuronal tissues, presenilin activity is required in terminally differentiated neurons in vivo. Mutations in the Caenorhabditis elegans presenilin genes sel-12 and hop-1 result in a defect in the temperature memory of the animals. This defect is caused by the loss of presenilin function in two cholinergic interneurons that display neurite morphology defects in presenilin mutants. The morphology and function of the affected neurons in sel-12 mutant animals can be restored by expressing sel-12 only in these cells. The wild-type human presenilin PS1, but not the FAD mutant PS1 A246E, can also rescue these morphological defects. As lin-12 mutant animals display similar morphological and functional defects to presenilin mutants, we suggest that presenilins mediate their activity in postmitotic neurons by facilitating Notch signalling. These data indicate cell-autonomous and evolutionarily conserved control of neural morphology and function by presenilins.     

CKMM基因A/G多态性与耐力、力量速度、混合型运动能力关联性的Meta分析

为探索肌型肌酸激酶(muscle-specific creatine kinase,CKMM)基因A/G单核苷酸多态性与耐力、力量速度、混合型运动能力的关联性,通过检索超星医学在线、万方数据库、维普数据库、中国生物医学文献服务系统、中国知网(CNKI)、中国科学引文数据库(CSCD)、EBSCO数据库、PubMed、Science Direct及Web of Science中CKMM基因A/G多态性与耐力、力量速度、混合型运动能力关联性的相关研究,采用Review Manager 5.3对纳入研究进行荟萃分析(Meta-analysis).结果表明:耐力运动员CKMM基因多态性与耐力运动能力、速度力量及混合型项目运动能力不存在显著关联(P>0.05).根据人种进行亚组分析发现,亚洲及欧洲人群CKMM基因A/G多态性等位基因、显性基因及杂合子模型与耐力运动能力均存在显著关联(P<0.05);亚洲优秀耐力运动员表现为G等位基因增加,欧洲优秀耐力运动员表现为A等位基因增加.由此可见,CKMM基因A/G多态性可作为亚洲及欧洲耐力运动员选拔指标,但应考虑不同种族人群A:G等位基因差异.     

怀牛膝多糖对肺腺癌细胞系凋亡的调节

目的:研究怀牛膝多糖的抗肿瘤作用.方法:应用MTT法检测怀牛膝多糖在体外对肺腺癌细胞系(LTEP-a-2)增殖的调节,同时采用流式细胞术(FCM)检测其对LTEP-a-2细胞周期和凋亡的影响.结果:怀牛膝多糖对LTEP-a-2的增殖具有抑制作用,并可以诱导其凋亡.结论:怀牛膝多糖在体外能抑制肺癌细胞的生长,可作为一种抗肺癌药物.     

红景天苷对BMSC生物学特性影响

目的：研究红景天苷对骨髓间充质干细胞（Bonemesenchymalstemcells,BMSCs）生物学活性影响。方法：采用贴壁法分离培养BMSCs,检测细胞表面分子表达对所获干细胞进行鉴定。以终浓度为10¨g／mL红景天苷与BMSCs共培养,通过形态学观察和MTT法分析研究其对BMSCs生物学特性影响。结果：成功培养出BMSCs,免疫荧光染色显示,培养的第3代BMSCs表达CD29、CD44干细胞标志。10μg／mL红景天苷与BMSCs共培养后,较对照组细胞生长更为旺盛,更为规整,形成典型的“鱼群状”。生长曲线显示,实验组细胞较对照组生长稳定,增殖能力活跃。结论：10μg／mL红景天苷可促进BMSCs增殖分化,又不影响细胞增殖分化等生物学特性。