高山红景天细胞悬浮培养中pH值对红景天甙胞外释放及细胞活性…

高山红景天细胞悬浮培养中,通过降低培养基ＰＨ值能有效地诱导培养细胞中红景天甙的胞外释放。红景天甙的跨膜运输是一个有与Ｈ对运的动态过程,培养基ＰＨ值决定了红景天甙在胞内外含量的分布。细胞组织在ＰＨ值大于３的培养基中处理３ｈ以内,对细胞活性的影响不大。将诱导释放处理过的细胞转入到新鲜的生产培养基中,细胞仍具有合成红景天甙的能力。     

高山红景天细胞悬浮培养中红景天甙生物合成代谢调控Ⅱ:真菌诱导物的影响

考察了6种真菌诱导物对高山红景天(Rhodiola sachalinensis A. Bor)细胞生长与红景天甙积累的影响。其中以黑曲霉诱导物效果最好。在细胞培养初期添加浓度为10mg(carbohydrate)/L的黑曲霉诱导物能使培养细胞中红景天甙含量提高到0.995％。前体与诱导物调控组合运用最终使红景天甙产量达到167.4mg/L,是对照培养的3.5倍。另外,对真菌诱导物的作用机理也进行了探讨,真菌诱导物添加促进红景天甙的积累应该与激活培养细胞中的苯丙烷类代谢途径有关。     

高山红景天细胞悬浮培养中红景天甙生物合成代谢调控Ⅱ：真 …

考察了６种真菌诱导物对高山红景天（Ｒｈｏｄｉｏｌａ ｓａｃｈａｌｉｎｅｎｓｉｓ,Ｂｏｒ）细胞生长与红景天甙积累的影响。其中以黑曲霉诱导物效果最好。在细胞培养初期添加浓度为４０ｍｇ（ｃａｒｂｏｈｙｄｒａｔｅ）Ｌ的黑曲霉诱导物能使培养细胞中红景天甙含量提高到０．９９５％。前体与诱导物调控组合运用最终使红景天甙产量达到１６７．４ｍｇ／Ｌ,是对照培养的３．８倍。另外,对真菌诱导物的作用机理也进行了探讨,真     

利用高山红景天培养细胞生物转化外源酪醇生产红景天甙的研究

高山红景天（ＲｈｏｄｉｏｌａｓａｃｈａｌｉｎｅｎｓｉｓＡ．Ｂｏｒ．）培养细胞中,甙元酪醇在细胞生长静止期大量积累,而此时糖基化反应的效率很低,因而红景天甙（ｓａｌｉｄｒｏｓｉｄｅ）产量较低。考虑到培养细胞中酪醇葡萄糖基转移酶的活性在指数生长期达到最高,考察了在指数生长期添加外源酪醇生物转化生产红景天甙的可能性,并探讨了酪醇添加浓度、添加方法及细胞密度对酪醇转化率及红景天甙产量的影响。结果表明,细胞在酪醇浓度为１ｍｍｏｌ／Ｌ的培养基中培养２４ｈ后可使酪醇转化率达到９５％;过高的酪醇浓度（＞３ｍｍｏｌ／Ｌ）对细胞生长及酪醇转化率都有明显抑制作用;通过较低浓度酪醇的３次重复添加,可使细胞密度为６ｇＤＷ／Ｌ、１２ｇＤＷ／Ｌ及１８ｇＤＷ／Ｌ的培养物中的红景天甙产量分别达到１３２０ｍｇ／Ｌ、１７４０ｍｇ／Ｌ和１９８０ｍｇ／Ｌ。     

狭叶红景天愈伤组织中红景天甙含量及相关代谢酶活力的研究

室温下分别对狭叶红景天的茎和叶进行愈伤组织诱导,在24C和4C进行继代培养,测定其苯丙氨酸解氨酶、肉桂酸-4羟化酶和酪氨酸解氨酶的活性,并利用高效液相色谱法测定其红景天甙含量。结果表明：培养温度和愈伤组织的外植体来源均影响红景天甙的含量和3种代谢酶的酶活力;在24C和4C温度条件下,相同外植体来源的愈伤组织叶中和相同培养温度条件下的茎和叶2种不同来源外植体的愈伤组织中,红景天甙含量和3种代谢酶活力之间均存在显著性差异。     

利用FRET技术在活细胞内研究红景天甙对Aβ25-35诱导PC12细胞凋亡的抑制作用

为研究红景天甙(salidroside)对-淀粉样肽25-35(.amyloidpeptide25-35,A/25-3)5诱导PC12细胞凋亡的抑制作用,采用CellCountingKit-8(CCK-8)分析细胞的存活率,通过光镜检测细胞形态并配以Hoechst染色检测细胞核固缩,利用荧光共振能量转移(fluorescenceresonanceenergytransfer,FRET)技术在单个活细胞中检测caspase-3和caspase-8活性的动态变化。结果表明,红景天甙可剂量依赖性抑制A025-35引起的细胞凋亡,提高细胞的存活率;红景天甙对caspase-3的活性有明显的抑制作用,而且A125-35诱导细胞凋亡不依赖于caspase-8的激活。这些结果提示抑制caspase-3的活性是红景天甙抑制A225-35诱导PC12细胞凋亡的机制之一。     

光强和光质对野外栽培高山红景天生物量和红景天甙含量的影响

为探讨野外条件下光强及光质对高山红景天 (Rhodiola sachalinensis)生物量和红景天甙含量的影响 ,于 2 0 0 1年 5月 8日至 9月 16日在大兴安岭加格达奇的高山红景天种植圃地 ,利用纱布及红色、蓝色和绿色的滤光膜遮光处理 ,对生长 3a和 4 a的高山红景天进行了光强、光质控制实验。与温室实验类似 ,遮荫显著抑制高山红景天根的生长 ,并使红景天甙的含量略有提高。红膜处理使光强大约降低一半 ,但仅从光质的角度而言 ,红膜处理对根的生长影响不大 ,却显著增加了根中的红景天甙含量和产量 ,不过效果不如温室实验明显。绿膜处理未表现出对红景天甙积累的促进作用 ,这与温室实验结果不同。红膜处理不同天数的结果表明 ,处理时间对红景天甙含量提高的程度影响很小。这意味着在野外种植的情况下 ,可以在临近收获的最后一段时间用红膜对高山红景天进行处理 ,这样既可避免红膜处理对高山红景天根生长的抑制 (由于减弱了光照 ) ,又可显著提高根的红景天甙含量 ,从而达到大幅度提高红景天甙产量的目的。     

长鞭红景天悬浮培养细胞的玻璃化法超低温保存研究

对长鞭红景天悬浮培养细胞的玻璃化法超低温保存进行了初步研究.结果表明,预培养、预处理、脱水处理及冻后处理对长鞭红景天悬浮培养细胞存活率均有重要影响,方差分析结果均显示差异显著.长鞭红景天悬浮培养细胞过程中最佳培养条件是:在含5%二甲基亚砜(DMSO)的MS培养基上预培养1 h,室温下80%PVS2预处理40 min,然后用100%PVS2于0℃处理50 min,投入液氮(LN)保存1 h后在40℃水浴中迅速化冻,再用1.2 mol/L蔗糖培养液洗涤3次,每次10 min,洗涤后的悬浮培养细胞用氯化三苯四氮唑(TTC)法检测,其存活率可达72.70%.     

利用FRET技术在活细胞内研究红景天甙对Aβ25-35诱导PCI2细胞凋亡的抑制作用

为研究红景天甙（salidroside）对β淀粉样肽25-35（β amyloid peptide25-35,Aβ25-35）诱导PC12细胞凋亡的抑制作用,采用Cell Counting Kit-8（CCK-8）分析细胞的存活率,通过光镜检测细胞形态并配以Hoechst染色检测细胞核固缩,利用荧光共振能量转移（fluorescence resonance energy transfer,FRET）技术在单个活细胞中检测caspase-3和caspase-8活性的动态变化。结果表明,红景天甙可剂量依赖性抑制Aβ25-35引起的细胞凋亡,提高细胞的存活率;红景天甙对caspase-3的活性有明显的抑制作用,而且Aβ25-35诱导细胞凋亡不依赖于caspase-8的激活。这些结果提示抑制caspase-3的活性是红景天甙抑制Aβ25-35诱导PC12细胞凋亡的机制之一。     

温室栽培光强和光质对高山红景天生物量和红景天甙含量的影响

为探讨光强及光质对高山红景天(Rhodiola sachalinensis)生物量和红景天甙含量的影响。于2000年4月至6月在东北林业大学温室内以移栽于大兴安岭加格达奇圃地人工种植生长3a的高山红景天为材料,通过纱布遮荫及遮以不同颜色的滤光膜分别进行了光强、光质控制实验(处理45d)。随着光强的降低,高山红景天全株生物量、根生物量、根的红景天甙含量和产量以及叶中叶绿素a、叶绿素b、总叶绿素的含量均有降低的趋势,但叶绿素含量变化很小,不同光强及对照之间的差异均未达到显著水平。相对光强为67．75％和44．71％的两种处理下的全株生物量、根生物量、根的红景天甙含量和产量差异不显著,它们的全株生物量和红景天甙含量与对照(全光照)的差异也不显著,但根生物量和红景天甙产量与对照的差异显著。当相对光强减弱至31．96％,全株生物量、根生物量、根的红景天甙含量和产量均大幅度下降,根冠比显著增加。4种滤光膜处理均使高山红景天的全株生物量及根生物量显著降低,蓝膜和绿膜处理的降低幅度大于红膜和黄膜处理的。红膜处理的红景天甙的含量和产量均高于对照,但黄膜、蓝膜和绿膜处理的红景天甙含量和产量则低于对照。通过计算去除4种滤光膜的光强因素,仅从光质的作用看。4种滤光膜处理仍是减小了全株生物量和根生物量,红膜和绿膜处理提高了红景天甙的含量和产量,而黄膜处理降低了红景天甙的含量和产量,蓝膜处理几乎没有效果。4种滤光膜处理均使叶绿素含量增加,但只有蓝膜处理的与对照差异显著。红膜处理不仅显著提高根中红景天甙的含量(为对照的3．42倍),而且对根生物量的影响较小(为对照的90．24％)。因而提高了高山红景天根的红景天甙产量,这意味着在生产上可能会有一定的实践意义。     

真菌激发子对人参悬浮培养细胞的生长和人参皂甙生物合成的影响

真菌诱导子处理人参悬浮培养细胞后,人参皂甙的合成有明显增加,诱导处理改变人参皂甙的积累时程,促进人参细胞培养物中次生产物的外泌,同时增强细胞对蔗糖的摄取、吸收并引起细胞H~ 流的变化。     

高山红景天细胞悬浮培养中红景天甙生物合成代谢的调控 Ⅰ:前体的影响

探索了高山红景天(Rhodiola sachalinensis A.Bor)细胞培养中红景天甙生物合成的途径,认为甙元酪醇是经由莽草酸途径生成的。在此基础上研究了酪醇、L-酪氨酸与L-苯丙氨酸三种前体加入对红景天甙生物合成的调控作用。结果表明,酪醇、酪氨酸等前体易被多酚氧化酶氧化成褐色,用与前体浓度为1:1的V。来防止褐化效果显著;浓度为0.5mmol/L的酪醇,酪氨酸及苯丙氨酸在细胞培养15d时添加,使红景天甙含量由0.336％分别提高到1.43％、1.11％、0.85％。     

10升气升环流式生物反应器培养紫草细胞

本文采用自行设计研制的10升气升环流式生物反应器培养紫草细胞,培养周期34d．前14d为细胞生长培养,细胞生长呈正常的S型曲线,细胞增长到原细胞接人量的4倍．后20d为紫草色素生产培养,细胞增长到32倍。整个周期每升培养液可生产紫草色素0．6g,在反应器中,培养液pH值的变化与细胞生长呈正相关,与紫草色素的形成呈负相关,pH值变化规律可用于监测紫草细胞在生物反应器的生长和色素形成．     

pH AND POPULATION DENSITY IN THE REGULATION OF ANIMAL CELL MULTIPLICATION

Sparse and dense cultures of chick embryo cells were affected differently by pH. The rates of cell multiplication and of thymidine-³H incorporation into DNA of dense cultures were increased as the pH was increased from 6.6 to 7.6. At pH higher than 7.6 the rate of multiplication decreased slightly in the dense cultures, but the rate of thymidine-³H incorporation continued to increase. The discrepancy was due in part to cell death and detachment at very high pH, and in part to a more rapid uptake of thymidine-³H at very high pH. Sparse cultures were much less sensitive to pH reduction and, when a suitably conditioned medium was used to minimize cell damage, very sparse cultures grew almost as well at pH 6.7 as at higher pH. The rates of cell multiplication and thymidine-³H incorporation at low pH decreased in the initially sparse cultures before they reached confluent cell densities. There was no microscope evidence of direct contact between plasma membranes of cells at these densities although the parallel orientation indicated that the cells were influencing locally each other's behavior. Even at much higher cell densities, electron microscopy revealed large intercellular gaps partly filled with a fragmentary electron-opaque material suspected to be glycoprotein. Wounding experiments showed that pH affected cell migration in a manner similar to its effects on cell multiplication. Low pH inhibited cell migration, but those cells which migrated into the denuded region multiplied as rapidly at low pH as at high pH. The effects of pH on growth were correlated with effects on the uptake of 2-deoxyglucose-³H. Dense populations of cells inhibited by low pH were stimulated to incorporate thymidine-³H by the addition of small amounts of diethylaminoethyl-dextran. Rous sarcoma cells at high cell density were less sensitive to pH than were normal cells at the same density, but were more sensitive than sparse normal cultures. The results suggest that cell growth is inhibited through the combined effects of both lowered pH and high cell density on cell surface permeability.     

Salidroside ameliorated hypoxia-induced tumorigenesis of BxPC-3 cells via downregulating hypoxia-inducible factor (HIF)-1α and LOXL2

Herein, we found that salidroside suppressed hypoxia-inducible factor 1 alpha (HIF-1α) and lysyl oxidase-like protein 2 (LOXL2) within human pancreatic cancer BxPC-3 cells cultured both under normoxia and hypoxia condition. To investigate the effect of salidroside on tumorigenesis of BxPC-3 cells and whether HIF-1α and LXCL2 were involved in this process, cells transfected with or without LOXL2 overexpression vector, were treated with 50 μg/mL of salidroside or 50 μM of KC7F2 (a HIF-1α inhibitor) under hypoxia. Cell viability and invasion were assessed using CCK-8 and Transwell chamber assay, respectively. Expression of E-cadherin and matrix metalloproteinase 2/9 (MMP 2/9) was determined, by Western blot analysis, to assess cell mobility at molecular levels. We confirmed that hypoxia increased LOXL2 and induced tumorigenesis of BxPC-3 cells, as evidenced by promoted cell proliferation and invasion, enhanced MMP2/9 while reduced E-cadherin. Interestingly, hypoxia-induced carcinogenesis was significantly retarded by both salidroside and KC7F2, however, enhanced with LOXL2 overexpression. Besides, salidroside and KC7F2 reduced LOXL2, and reversed the tumorigenesis of BxPC-3 cells induced by LOXL2 overexpression. Given the inhibitory effect of salidroside on HIF-1α expression, our data suggested that: (1) LOXL2 was the mechanism, whereby salidroside and KC7F2 showed inhibitory effect on cancer progression of BxPC-3 cells; (2) salidroside exerted its anticancer effect, most likely, by a HIF-1α/LOXL2 pathway. In conclusion, salidroside was a novel therapeutic drug in pancreatic cancer, and downregulation of HIF-1α and LXCL2 was the underlying mechanism.     

THE SEPARATION OF DIFFERENT CELL CLASSES FROM LYMPHOID ORGANS : III. The Purification of Erythroid Cells by pH-Induced Density Changes

1. Mammalian erythrocytes swell as the pH of the isotonic suspending medium is lowered, as a direct consequence of the specialized permeability properties of the erythrocyte membrane. Lymphocytes and granulocytes from a variety of sources did not exhibit this property. 2. The behaviour of mouse bone marrow erythroid cells at various stages of differentiation was studied by using a change in buoyant density with pH as an index of swelling. The ability to swell with a pH drop was acquired while the cell was still nucleated. All non-nucleated cells showed swelling. Most small erythroblasts shared this property, whereas most large erythroblasts did not. 3. The density shift with pH was used to provide a purification scheme specific for erythroid cells. The bone marrow cells were first centrifuged to equilibrium in an isotonic albumin density gradient at neutral pH. Regions of the gradient containing the erythroid cells were collected, and the cells were recovered and redistributed in an albumin gradient at acid pH. The erythroid cells showed a specific density shift which removed them from contaminants. Preparations containing 90–97% erythroblasts were obtained by this technique. 4. Differentiation within the erythroid series was accompanied by a general increase in cell buoyant density at neutral pH. This density increase may have been a discontinuous process, since erythroid cells appeared to form a number of density peaks. 5. The pH shift technique, in association with established density distribution and sedimentation velocity procedures, provides a range of cell separation techniques for biological or biochemical studies of erythroid cell differentiation in the complex cell mixtures in bone marrow or spleen.     

红花细胞克隆的平板培养

在红花(Cathamus unctorrus)细胞克隆的平板培养中很多因素都能影响其植板率,如培养基的 pH 值,无机盐中的 NH_4NO_3、ZnSO_4、MnSO_4;有机酸中的柠檬酸、琥珀酸、苹果酸及延胡索酸,谷氨酰胺和精氨酸,葡萄糖,椰乳和水解乳蛋白等。向培养基中加入10mg/l 柠檬酸或3mg/l 琥珀酸能显著提高植板率。适量的人参寡糖及黑节草寡糖应用对促进红花细胞克隆生长取得很好效果。常规的高压灭菌最不利于细胞生长,在15磅/cm~2灭菌5分钟效果较好,过滤灭菌效果最好。     

RESPIRATORY ACTIVITY AND MAINTENANCE OF CELL SUSPENSIONS OF RAT LIVER

Previous experimentation involving the use of dispersed rat liver cells have utilized suspending media common to fractionation and slicing methods. Cells in these media have not remained viable for prolonged periods of time and they have resisted culturing techniques. Suspensions of dispersed parenchymal cells were prepared from rat livers which had been perfused in situ via the dorsal aorta with an EDTA-sucrose solution. The maintenance of surviving cells was attempted in three different media: sucrose buffered with Tris-HCl, Waymouth medium, and Waymouth medium supplemented with 30% calf serum. Cells suspended in sucrose and buffered with Tris-HCl oxidized citrate, succinate, and α-kegoglutarate but did not respire in the presence of other citric acid cycle intermediates. When cells were suspended in Waymouth medium without glucose, they oxidized malate and glutamate plus the above-mentioned substrates. Glucose and pyruvate did not stimulate oxygen uptake in either medium. Cells exhibited respiratory activity for up to 8 hr when incubated in Waymouth medium supplemented with calf serum. Both the ability to oxidize succinate and the morphological integrity of the cells were retained for this period of time. When cells were incubated in Waymouth medium alone, the time interval was reduced to 6 hr. Sucrose-Tris-HCl in the presence of succinate was not satisfactory as an incubation medium, since many of the cells underwent breakdown.     

MADP,a salidroside analog,protects hippocampal neurons from glutamate induced apoptosis

Aims

To investigate the anti-apoptotic effect of MADP, an analog of salidroside, against glutamate induced apoptosis in the cultured rat hippocampal neurons.

Main methods

Cytotoxicity was determined by the MTT method and lactate dehydrogenase release to the medium. Cell apoptosis was evaluated by Hoechst 33342 staining, TUNEL assay and flow cytometric analysis. Western blotting was applied for detecting protein levels of cellular signaling molecules.

Key findings

Our results showed that glutamate exposure significantly induces cell apoptosis, whereas the pretreatment of salidroside or MADP remarkably improves cell viability. Most importantly, the anti-apoptotic effect of MADP against glutamate insult is superior to salidroside. To explore the involved mechanisms, we measured some pro-apoptotic and anti-apoptotic protein levels, and several cell survival signaling pathways were analyzed as well. No visible alterations in Bcl-2 and Bax protein levels were observed by MADP or salidroside. Akt and JNK phosphorylation was robustly stimulated by MADP in the glutamate-treated neurons. Salidroside treatment results in a slight activation in Akt, while no significant alteration in JNK activity was observed.

Significance

MADP exhibits higher capacity to attenuate glutamate induced cell apoptosis in the cultured rat hippocampal neurons, suggesting that MADP might be a better candidate than salidroside for developing novel drugs treating neuron loss associated disorders.     

High yield production of salidroside in the suspension culture of Rhodiola sachalinensis

Salidroside has been identified as the most potent ingredient of the Chinese medicine herb, Rhodiola sachalinensis. Since the natural supply of this herb is rapidly decreasing, we established a compact callus aggregate (CCA) strain and culturing system for high yield salidroside production. Several callus strains induced from the explants originated from root, stem, leaf and cotyledon of R. sachalinensis were established and screened for rapid growth rate, high salidroside content and easy propagation in suspension culture condition. The CCA strain was established from a callus strain initiated from the cotyledon. The kinetics of dry weight accumulation and cellular salidroside content in various culture conditions for the strain was determined. For high salidroside production, the optimal inoculum amount was 10% and the optimal concentration for 6-benzylaminopurine and indole-3-butyric acid added in the liquid medium was 5 and 2.5 mg l-1, respectively. The acidic culture medium and a faster shaking speed favored the salidroside accumulation. The addition of 2,4-D, in the liquid MS medium and the utilization of L-tyrosol for chemical feeding enhanced salidroside production. Using a proper combination of culture condition and treatment, salidroside accumulation could reach 57.72 mg g-1 dry weight, that was 5-10-fold higher than that detected in field-grown plants. The corresponding salidroside yield was 555.13 mg l-1, a level suitable for cost effective commercial production to compensate the natural resource shortage of R. sachalinensis.