小鼠肺癌细胞诱导分化后的力学特性比较

通过鬼笔环肽染色技术观察比较了小鼠肺癌细胞经诱导分化后的微丝变化,利用免疫印迹技术测定了小鼠肺癌细胞经诱导分化后α-SMA蛋白含量的变化,利用CTFM法测定了小鼠肺癌细胞在诱导分化后的牵引力变化.结果发现,小鼠肺癌细胞在诱导分化后,细胞的形态及微丝骨架均发生了变化,同时,α-SMA蛋白含量明显增多并且变得集中;细胞投影面积显著增大,约增37%;细胞牵引力也显著增强,均方根值大约增加了一倍.这说明细胞骨架、细胞的形态、α-SMA蛋白和细胞牵引力均与细胞的癌变过程有密切关系.     

人骨髓间充质干细胞不同亚群

为比较不同亚群的人骨髓间充质干细胞(human bone mesenchymal stem cell, hBMSC)自我更新和分化能力,通过获赠的人髂骨骨髓标本,联合运用密度梯度离心和差异贴壁法分离MSCs , 用10 μm 滤膜将不同群体细胞分离,倒置相差显微镜观察不同亚群细胞的形态;流式细胞仪检测BMSC不同亚群细胞的表型;在地塞米松、Vit C、β-磷酸甘油钠作用下将不同亚型细胞向成骨细胞诱导分化,分别观察其分化能力.结果成熟的MSC,即mMSCs 细胞(mature cells)呈纤维样梭形, RS 细胞(rapidly MSC self-renewing cells)呈圆形.RS细胞增殖能力明显强于mMSCs.经定向诱导分化后,RS细胞向成骨细胞分化能力较mMSCs细胞强.说明RS 细胞较之mMSC细胞可能是一种更原始的中胚层前体细胞,具有更强的自我更新和分化潜能.     

人参皂甙Rg1对人成骨肉瘤MG-63细胞形态结构和终末分化指标的影响

为了研究人参皂甙Rg1对人成骨肉瘤MG-63细胞(以下简称"MG-63细胞")形态与超微结构及终末分化指标的影响,鉴定其对MG-63细胞的诱导分化作用,以50 μg/mL人参皂甙Rg1处理MG-63细胞,光学显微镜与电子显微镜观察MG-63细胞形态、超微结构变化,免疫细胞化学方法检测成骨细胞相关终末分化蛋白的表达变化,并同步以HMBA处理MG-63细胞作为阳性对照.光学显微镜与电子显微镜观察结果显示细胞形态与超微结构产生了细胞形态规则、大小一致、细胞铺展体积增大,核质比例减小、核内核仁数目减少、细胞器丰富发达等与正常细胞相似的恢复性变化.观察到MG-63细胞终末分化指标I型胶原、骨粘素、骨钙蛋白的阳性表达及钙化糖原颗粒的增多与典型骨节结的形成,其变化结果与HMBA处理细胞类似.本研究证实人参皂甙Rg1能显著改变MG-63细胞形态与超微结构恶性特征,并增强成骨细胞相关的终末分化指标的表达,从而对MG-63细胞的终末分化具有一定的诱导作用.     

人骨髓间充质干细胞不同亚群

目的 比较不同亚群的人骨髓间充质干细胞(human bone mesenchymal stem cell, hBMSC)自我更新和分化能力。方法 通过获赠的人髂骨骨髓标本,联合运用密度梯度离心和差异贴壁法分离MSCs , 用10μm 滤膜将不同群体细胞分离,倒置相差显微镜观察不同亚群细胞的形态;流式细胞仪检测BMSC不同亚群细胞的表型;在地塞米松、Vit C、β-磷酸甘油钠作用下将不同亚型细胞向成骨细胞诱导分化,分别观察其分化能力。结果 成熟的MSC,即mMSCs 细胞(mature cells)呈纤维样梭形, RS 细胞(rapidly MSC self-renewing cells)呈圆形。RS细胞增殖能力明显强于mMSCs。经定向诱导分化后,RS细胞向成骨细胞分化能力较mMSCs细胞强。结论 RS 细胞较之mMSC细胞可能是一种更原始的中胚层前体细胞,具有更强的自我更新和分化潜能。     

人胃腺癌细胞系恶性表型逆转过程中细胞骨架变化的初步研究

应用显示细胞骨架的光镜和电镜方法观察表明,MGc80-3细胞质内微管很少,中间纤维数量稀少、构型改变,质膜内缘有较丰富的微丝层,具有恶性细胞典型的、不发达的细胞骨架特征.但经dBcAMP诱导后,细胞质内微管和中间纤维数量增多,分布排列有规则,质膜内缘微丝大量减少,细胞骨架组成、构型、数量与分布均产生与正常细胞大体相似的恢复性改变.这种变化是由于dBeAMP诱导胃癌细胞内cAMP水平的提高而实现的.细胞骨架正常构型和功能的恢复,对于逆转细胞形态结构的改变、细胞增殖的调控和细胞表面特性的改变均具有重要影响,是癌变细胞恶性表型逆转的一种重要的形态和功能表现.     

小鼠胸腺瘤细胞程式死亡调控的初步研究

通过对小鼠胸腺瘤细胞的筛选,获得了具T_(cR)V_~+CD4~+CD_~+表型的CD11.3-D_2细胞株,钙离子载体lonomycin能够诱导其死亡,而抗CD_3单克降抗体却不能介导它死亡,CD11.3-D_23细胞可作为研究细胞程式死亡(Programmed Cell Death)机理和胸腺细胞发育分化机理的体外模型.     

细胞转化过程中微丝解聚的研究

ＮＩＨ３Ｔ３细胞以劳氏肉瘤病毒（ＲＳＶ）经温度敏感突变株转染形成的细胞株ｔｓＬＡ９０，细胞在允许温度（４０℃）时为正常表型，在允许温度（３３℃）下为转化表型。４０℃时，微丝分布发达，从４０℃移至３３℃１ｈ，微丝完全解聚，同时，其外基质成分纤粘蛋白（ＦＮ）亦相伴解聚。若在４０℃以外源性ＦＮ或对蛋白激酶Ｃ（ＰＫＣ）具有抑制作用的三氟拉嗪进行预处理后，再转入３３℃时便能抑制微丝的解聚。结果提示，除ＲＳＶ     

淫羊藿对RANKL、M-CSF诱导的破骨样细胞形成及FN表达的影响

建立RANKL、M-CSF诱导的破骨样细胞体外培养体系,采用细胞染色分析研究淫羊藿对RANKL和M-CSF诱导全骨髓细胞分化形成破骨样细胞的作用,并探讨FN在破骨样细胞形成过程中的作用,结果显示,淫羊藿能够抑制RANKL、M-CSF诱导的破骨样细胞的形成,FN与破骨样细胞的融合有关.     

小鼠颌下腺组织培养上清液诱导K562细胞向红系分化的研究

小鼠颌下腺组织培养上清液 (SGCM )能诱导K5 6 2细胞向红系分化 ,其诱导作用随SGCM浓度的增加而增加 ;小鼠SGCM能抑制K5 6 2细胞的生长 ,改变K5 6 2细胞的生长曲线 ,而这种抑制作用是细胞被诱导分化所致 ;K5 6 2细胞的生长抑制与SGCM浓度呈正相关 .SGCM中加入红细胞生成素 (EPO)抗体或胰岛素样生长因子 (IGF) Ⅱ抗体 ,其诱导活性没有降低 ,显示SGCM中可能另有诱导K5 6 2细胞向红系分化的因子存在 .     

NGF诱导PC12细胞神经元样细胞分化

目的:建立PC12细胞的神经元样细胞分化模型,并探讨ERK蛋白在PC12细胞神经元样细胞分化中的可能机制.方法:以10、20、50 g/L的NGF(NGF溶于PBS,培养基中PBS的终浓度不超过2%)培养PC12细胞,应用倒置相差显微镜、显微镜测微尺及流式细胞仪鉴定PC12细胞的分化,以确定NGF使用剂量.运用免疫印迹检测不同浓度、不同作用时间时ERK蛋白在PC12细胞中的表达,并进行统计学分析.结果:随NGF剂量的升高,PC12细胞的体积、最长突起长度和突起数目均会增大或增多。统计学分析证明50 g/L的NFG作用48 h足以诱导PC12细胞的交感神经样改变。尽管ERK总蛋白水平在NFG作用前后无明显改变,但在NFG作用5 min后磷酸化的ERK蛋白水平即显著升高,达到峰值,并持续约1 h.50 g/L的NFG作用于PC12细胞48 h可使细胞发生明显的G1期阻滞.结论:PC12细胞可在NGF作用下出现交感神经样改变,并且细胞的分化程度依赖于NGF的使用剂量和作用时间.在NGF诱导的PC12细胞神经元样分化中ERK蛋白的磷酸化对NGF呈现剂量和时间依赖性,提示ERK蛋白在分化的早期发挥重要作用.     

HMBA诱导人成骨肉瘤MG-63细胞分化过程中核基质蛋白表达变化

应用选择性抽提、双向聚丙烯酰胺凝胶电泳技术分析5mmol/LHMBA诱导处理前后人成骨肉瘤MG 63细胞核基质蛋白表达变化,鉴定与人成骨肉瘤细胞增殖分化相关的特异核基质蛋白.实验结果显示在HMBA诱导处理MG 63细胞分化过程中,核基质蛋白NMP 1、NMP 2、NMP 3、NMP 4、NMP 5、NMP 6和NMP 7等7个蛋白点表达发生显著变化.其中NMP 1仅在MG 63细胞中表达,NMP 6则为经HMBA诱导处理后新出现的蛋白质,NMP 2、NMP 7在HMBA诱导分化细胞中表达减弱,而NMP 3、NMP 4和NMP 5则在诱导分化后细胞中表达增强.首次表明在人成骨肉瘤MG 63细胞诱导分化过程中伴有核基质蛋白表达的差异,证实了与肿瘤细胞增殖分化相关的特异核基质蛋白的存在.这对于揭示核基质蛋白与细胞癌变和逆转的关系、阐明细胞增殖分化的基因表达调控原理,均具有重要意义.     

Interaction of plasma membrane fibronectin receptor with talin--a transmembrane linkage

Many observations suggest the presence of transmembrane linkages between the cytoskeleton and the extracellular matrix. In fibroblasts both light and electron microscopic observations reveal a co-alignment between actin filaments at the cell surface and extracellular fibronectin. These associations are seen at sites of cell matrix interaction, frequently along stress fibres and sometimes where these bundles of microfilaments terminate at adhesion plaques (focal contacts). Non-morphological evidence also indicates a functional linkage between the cytoskeleton and extracellular matrix. Addition of fibronectin to transformed cells induces flattening of the cells and a reorganization of the actin cytoskeleton, with the concomitant appearance of arrays of stress fibres. Conversely, disruption of the actin cytoskeleton by treatment with cytochalasin B leads to release of fibronectin from the cell surface. As yet, there is no detailed knowledge of the molecules involved in this transmembrane linkage, although several proteins have been suggested as candidates in the chain of attachment between bundles of actin filaments and the cytoplasmic face of the plasma membrane: these include vinculin, alpha-actinin and talin, each one having been identified at regions where bundles of actin filaments interact with the plasma membrane and underlying cell-surface fibronectin. Recently, the cell-substrate attachment (CSAT) antigen has been identified as a plasma membrane receptor for fibronectin, raising the possibility that this glycoprotein complex may serve as a bridge between fibronectin and one or more of the underlying cytoskeletal components mentioned. Here we have investigated the interaction of the purified CSAT antigen with these cytoskeletal components, and we demonstrate an interaction specifically between the CSAT antigen and talin.     

HMBA对人成骨肉瘤MG-63细胞形态结构和终末分化指标表达的影响

应用环六亚甲基双乙酰胺处理人成骨肉瘤MG-63细胞,观察MG-63细胞处理前后形态与超微结构及其相关终末分化指标的表达变化.实验结果显示,经5 mmol/L HMBA处理后,MG-63细胞体积增大,趋于扁平铺展状态,细胞大小较为一致,排列较为规则,细胞核形态规则,核质比例减小,核仁减少,核内异染色质减少,常染色质增多,细胞核内的线粒体和高尔基体较为发达,内质网数量增多,细胞表面的微绒毛减少,在成熟细胞中可见钙化糖原颗粒,细胞表面出现钙化小泡沉积,并且形成典型的骨结节.常规细胞化学和免疫细胞化学检测显示,HMBA处理后的细胞中Ⅰ型胶原纤维、骨钙素、骨粘素的表达显著增加,实验结果表明HMBA能够有效诱导人成骨肉瘤细胞的分化,并促进其终末分化指标的表达.     

DNA-protein interaction at erythroid important regulatory elements of MEL cells byin vivo footprinting

Using ligation-mediated PCR method to study the status of DNA-protein interaction at hypersensitive site 2 of locus control Region and β^maj promoter of MEL cell line before and after induction, MEL cell has been cultured and induced to differentiation by Hemin and DMSO, then the live cells have been treated with dimethyl sulfate. Ligation mediated PCR has been carried out following the chemical cleavage. The results demonstrate that before and after induction, the status of DNA-protein interaction at both hypersensitive site 2 and β^maj promoter change significantly, indicating that distal regulatory elements (locus control region, hypersensitive sites) as well as proximal regulatory elements (promoter, enhancer) of β-globin gene cluster participate in the regulation of developmental specificity.     

HMBA诱导红白血病细胞分化作用的研究

目的：研究HMBA对红白血病细胞的抑制及诱导分化作用．方法：绘制HMBA作用下的红白血病细胞生长曲线，计数其分裂指数，联苯胺染色法检测其分化百分率．结果：红白血病细胞在HMBA作用下增殖能力下降，分裂指数减低，联苯胺染色阳性率为76％．结论：HMBA能抑制红白血病细胞生长繁殖并可诱导其分化．     

基于有限元法的活细胞粘附问题的力学建模及分析

活细胞粘附在诸如细胞生长、分化、移动和死亡等行为中扮演着重要的角色.同时,基底的力学特性也显著影响着活细胞粘附.为了找出并解释基底力学参数对细胞粘附行为的影响,本文尝试提出了一种弹簧绑定的力学模型.在该模型中,粘附力由处于粘附区域并连接细胞表面和基底表面的弹簧所表示,细胞和基底则分别由弹性壳体和固体所描述.通过改变细胞...     

HMBA单独或与HMBPA联合作用对MELDS19细胞生长及分化影响的研究

目的研究HMBA单独或与HMBPA联合作用对MELDS19细胞的抑制及诱导分化作用.方法绘制HMBA单独或与HMBPA联合作用下的MELDS19细胞生长曲线,联苯胺染色法检测其分化百分率,成集落实验检测细胞增殖情况.结果 MELDS19细胞在HMBA与HMBPA联合作用下增殖能力下降,联苯胺染色阳性率增高.结论 HMBA与HMBPA联合作用能增强抑制MELDS19细胞的生长繁殖及诱导其分化能力.     

Expression of c-myc changes during differentiation of mouse erythroleukaemia cells

The transforming gene of avian myelocytomatosis virus MC29, v-myc, causes a variety of malignancies in chickens. A cellular homologue, c-myc, has been implicated in B-cell malignancies in mice and humans but is also expressed in many normal cell types and may be important in the control of normal cell proliferation. c-myc is highly conserved in vertebrates. We have been investigating the relationship between c-myc expression and the terminal differentiation of cultured mouse erythroleukaemia (MEL) cells. We find that the level of c-myc messenger RNA shows a rapid biphasic change in MEL cells induced to differentiate by dimethyl sulphoxide or hypoxanthine. The changes occur during the first few hours of the differentiation programme and require active protein synthesis. These data suggest that changes in c-myc expression may be important in the irreversible commitment of MEL cells to terminal erythroid differentiation.     

Fibronectin inhibits the terminal differentiation of human keratinocytes

In the epidermis proliferation of keratinocytes is restricted to the basal layer, which is in contact with the basement membrane, and cells undergo terminal differentiation as they move upwards through the suprabasal layers. In stratified cultures of human keratinocytes, upward migration is a consequence, not a cause, of terminal differentiation and occurs because keratinocytes become less adhesive to their substratum and to one another. Most keratinocytes can be induced to differentiate to completion by placing them in suspension in methylcellulose: within 12 h DNA synthesis is irreversibly inhibited and by 24 h most cells express involucrin (ref 4; P. A. Hall, J.C.A. and F.M.W., unpublished observations). Here we report that when fibronectin is added to the methylcellulose, keratinocytes still withdraw from the cell cycle, but induction of involucrin expression is largely inhibited. The effect of fibronectin is concentration- and time-dependent and is mediated by a receptor of the integrin family. These results provide an explanation for why overt terminal differentiation is normally restricted to suprabasal cells, whereas cell-cycle withdrawal occurs within the basal layer; they also have important implications for the mechanism of epidermal wound healing. Furthermore, our data show that the binding of an extracellular matrix protein to its receptor can regulate differentiated gene expression in the absence of changes in cell shape.     

小麦根尖细胞分化过程中微丝骨架分布格局

以异硫氰四甲基若丹明－鬼笔环肽为探针,对小麦根尖三个不同发育区－分生区、伸长区和成熟区细胞中肌动蛋白纤丝（ＡＦｓ）的分布格局进行荧光显微观察和分析。结果表明：分生区细胞中细胞核为ＡＦｓ网络包围,细胞周缘有ＡＦｓ密集分布,胞质皮层中有ＡＦｓ有广泛均匀的分布;伸长区细胞中细胞核亦为网络包围,并明显可见ＡＦｓ成束由核周围向四处辐射直到细胞周质,且与分布于细胞边缘的ＡＦｓ汇集;成熟区细胞中伴随着核移向细胞