热休克蛋白70在人食管癌EC9706细胞凋亡过程中的表达与定位变化

目的 探讨姜黄素对人食管癌EC9706细胞凋亡的诱导作用,热休克蛋白70(HSP70)在肿瘤细胞凋亡过程中在核基质上的变化及其与凋亡调控相关蛋白的关系.方法 用细胞计数和流式细胞仪检测姜黄素对人食管癌EC9706细胞的增殖抑制作用,以光学显微镜和透射电镜观察姜黄素诱导人食管癌EC9706细胞凋亡前后的细胞结构变化,琼脂糖凝胶电泳观察人食管癌EC9706细胞凋亡前后的DNA结构变化.双向凝胶电泳和质谱鉴定分析HSP70在核基质中的存在与变化;并以Western blotting进行确证;激光扫描共焦显微镜观察HSP70在EC9706细胞凋亡过程中的定位及其与Bax、Bcl-2等基因产物的共定位关系.结果 姜黄素能显著抑制人食管癌EC9706细胞增殖并诱导人食管癌EC9706细胞凋亡,双向凝胶电泳、质谱鉴定和结果 发现并证实,HSP70在姜黄素处理前后的EC9706细胞核基质蛋白中的存在及其表达下调变化.激光扫描共焦显微镜观察结果 显示,HSP70在EC9706细胞凋亡过程中与Bax、Bcl-2等基因产物具有共定位关系,且其共定位区域发生了变化.结论 姜黄素对人食管癌EC9706细胞具有显著的凋亡诱导作用;HSP70作为一种新发现的核基质蛋白,在姜黄素诱导人食管癌EC9706凋亡过程中的表达与分布发生了显著变化.HSP70与凋亡相关基因的关系对EC9706细胞凋亡具有重要影响.     

伪狂犬病病毒Ea株诱导牛肾细胞凋亡及核基质蛋白的变化

目的研究伪狂犬病病毒(PrV)是否具有诱导组织培养细胞发生细胞凋亡的功能及探讨凋亡细胞核基质蛋白表达的变化。方法利用锥虫蓝(台盼蓝)染色绘制PrV在不同细胞上的增殖曲线;荧光染色观察凋亡细胞核的形态特征;琼脂糖凝胶电泳分析细胞染色体DNA的片段化;高分辨率双向电泳分析细胞凋亡前后核基质蛋白的表达差异。结果膜通透性的DNA特异性结合染料Hoechst 33342染色显示,PrV感染后36h,牛肾(MDBK)细胞核染色质开始固缩、凝聚,细胞核碎裂;DNA提取及琼脂糖凝胶电泳分析表明,细胞染色体DNA发生片段化,形成“DNA梯状”条带(DNA ladder);尽管PrV可以诱导MDBK细胞发生细胞凋亡,但不能诱导IBRS-2,BHK-21及PK-15细胞发生凋亡。MDBK细胞发生凋亡前后核基质蛋白的表达发生改变,存在表达上调、下调、诱导表达及表达遏制等情况。结论PrV诱导细胞发生细胞凋亡是其致细胞死亡的形式之一,间接反映了PrV与宿主细胞间复杂的相互作用。细胞凋亡前后核基质蛋白表达存在的差异说明PrV致MDBK细胞发生凋亡是自身基因产物或诱导或抑制宿主细胞基因表达的结果。     

Caspase-3 mRNA反义核酸对γ-射线诱导的HL-60细胞凋亡的影响

目的　观察caspase 3mRNA反义寡核苷酸 (ASODN)对HL 6 0细胞凋亡的抑制作用 ,筛选有效ASODN。　方法　用脂质体介导法将针对caspase 3mRNA不同序列的 4条ASODN导入HL 6 0细胞中 ,γ 射线照射。应用电泳法检测DNA梯状条带 ;Hoechst332 5 8 碘化丙啶染色 ,荧光显微镜分析凋亡细胞百分率 ;流式细胞术进行细胞凋亡定量。　结果　以caspase 3mRNA 5′非编码区 (- 6 2至 - 4 6位 )与编码起始区 (- 1至 16位 )ASODN转染 ,当转染终浓度≥ 3μmol L时 ,DNA电泳梯状条带消失 ,流式细胞术亦未见明显的亚二倍体峰 ;荧光染色分析 ,凋亡细胞百分率比未转染对照组和错配寡核苷酸对照组显著降低 (P <0 0 1) ,且随转染终浓度的增加 ,凋亡抑制率显著增加。另外 ,5′非编码区ASODN的抑制作用显著强于编码起始区ASODN(P <0 0 5 )。　结论　caspase 3mRNAASODN可抑制γ 射线诱导的HL 6 0细胞凋亡 ,其作用有序列特异性及剂量依赖性     

无血清培养体系中CD3AK细胞诱导HL—60细胞凋亡的研究

目的：采用无血清培养体系,研究CD3单克隆抗体激活的杀伤（CD3AK）细胞诱导HL－60细胞凋亡情况。方法：用血清代用品代替人血清培养CD3AK细胞,将诱导生成的CD3AK细胞与HL－60细胞共同孵育后,通过观察细胞形态、琼脂糖凝胶电泳检测DNA条带及充式细胞仪（FCM）检测分析HL－60细胞凋亡情况。结果：与CD3AK细胞孵育7h后的HL－60细胞出现凋亡细胞形态特征,DNA凝胶电泳典型梯状电泳带,FCM检测凋亡细胞比例为24.59%。结论：无血清培养条件下CD3AK细胞可诱导HL－60细胞凋亡。     

鲨鱼软骨抽提物诱导人胃癌细胞凋亡并下调Bcl-2表达

目的：探讨鲨鱼软骨抽提物(SCP)诱导人胃癌MGC80—3细胞调亡的作用机制。方法：以不同浓度SCP加入体外培养的MGC80—3细胞中，用MTT比色法检测细胞存活率；Hoeehst33342／PI荧光染色，荧光显微镜分析凋亡细胞百分率；流式细胞术进行细胞凋亡定量；琼脂糖凝胶电泳检测DNA梯状条带；免疫细胞化学染色法检测Bel-2蛋白的表达。结果：SCP明显抑制(MGC80—3细胞生长，IC50值为1mg／ml；荧光显微镜下可见60％以上细胞为凋亡细胞的形态学改变；琼脂糖凝胶电泳呈现梯状条带(DNA ladder)；免疫细胞化学检测显示Bcl-2表达明显降低。结论：SCP诱导人胃癌MGC80—3细胞凋亡，其作用机制可能与下调Bcl-2蛋白的表达水平有关。     

大鼠局灶性脑梗死后细胞凋亡及热休克蛋白70表达的变化

目的 探讨大鼠局灶性脑梗死后热休克蛋白70(HSP70)及细胞凋亡的变化。方法采用光化学法诱导制作大鼠局灶性脑梗死模型，冰冻切片行HSP70免疫组化染色，并用TdT-介导duTP-生物缺口末端标记(TUNEL)法检测凋亡细胞。结果免疫组化显示对照组和假手术组动物无HSP70免疫反应；局灶性脑梗死组12h即有：HSP70的表达，48h时HSP70表达至高峰，阳性反应局限于半暗带。TUNEL结果显示，对照组和假手术动物无凋亡细胞；局灶性脑梗死组6h时在半暗区凋亡细胞出现，3d达高峰。结论局灶性脑梗死可诱导HSP70的表达、神经细胞凋亡，两者的分布一致，但HSP70的表达高峰明显早于细胞凋亡。     

米托蒽醌对HL-60细胞的促凋亡效应

目的 :探索米托蒽醌 (MTN)促HL 6 0细胞凋亡效应及其机理。方法 :取对数生长期HL 6 0细胞 ,不同浓度MTN作用不同时间后 ,利用MTT法、透射电镜、DNA电泳、流式细胞术观察MTN对HL 6 0细胞的抑制效应、促凋亡效应及凋亡相关基因Bcl 2、Bax蛋白表达情况。结果 :(1)毫微克级的MTN对HL 6 0细胞有明显的抑制效应 ,且效应具有时间、剂量依赖关系。(2 )MTN作用后的HL 6 0细胞透射电镜观察胞膜完整、出现核碎裂、凋亡小体等形态学特征。DNA电泳出现 2 0 0bp左右的梯形条带。 (3)Bcl 2、Bax蛋白表达 :MTN作用于HL 6 0细胞相同时间 ,Bcl 2蛋白及Bcl 2蛋白与Bax蛋白比值 (Bcl 2 Bax)随MTN作用时间延长而下降。结论 :MTN具有诱导HL 6 0细胞凋亡作用 ,此过程中伴Bcl 2下调和Bcl 2 Bax的降低。提示MTN可能通过Bcl 2途径诱导HL 6 0细胞凋亡     

TRAIL诱导Hela细胞凋亡的线粒体信号通路

 目的 探讨 TRAIL 诱导人宫颈癌 Hela 细胞凋亡的线粒体通路。 方法 琼脂糖凝胶电泳判断细胞凋亡;激光共聚焦、Western blot、荧光免疫和 caspase-3 活性检测测定细胞线粒体膜电位 (∆Ψm) 、Bcl-2 蛋白、细胞色素 c (Cyt c) 和凋亡诱导因子 (AIF) 蛋白在细胞中的定位以及 caspase-3 活性。结果 TRAIL 能诱导 Hela 细胞凋亡,有凋亡细胞特有的 DNA 梯状条带。同时,TRAIL具有时间依赖性致 ∆Ψm 和 Bcl-2 蛋白含量明显下降,线粒体 Cyt c 蛋白释放,AIF 蛋白向细胞质、细胞核转移,caspase-3 活性增强。结论 TRAIL 诱导 Hela 细胞凋亡途径之一是通过线粒体信号通路进行的。     

人白细胞介素1β通过线粒体途径激活caspase-3诱导A375-S2细胞凋亡

目的研究人白细胞介素1β(Interleukin-1β,IL-1β)体外诱导人黑色素瘤A375-S2细胞凋亡的机制。方法通过Hoechst33258荧光染色,观察A375-S2细胞在IL-1β作用下的形态学变化。使用琼脂糖凝胶电泳法检测IL-1β对细胞DNA降解的影响。应用caspase活力测定法检测IL-1β对caspase-3活力的影响。利用Westernblot方法检测IL-1β对caspase-3底物的降解以及对细胞内Bcl-2家族和AIF蛋白表达的调节作用。结果IL-1β(1nmol/L)能够诱导A375-S2细胞凋亡,72h时细胞体变小,细胞核呈现固缩、断裂,并出现因凋亡引起的DNA梯状条带。IL-1β诱导细胞凋亡过程中,caspase-3的活力升高,其两种底物PARP和ICAD均发生降解,线粒体中抗凋亡蛋白Bcl-2和Bcl-xL的表达减少,促凋亡蛋白Bax的表达增加。凋亡诱导因子AIF蛋白的表达也有所增加。结论IL-1β通过激活caspase-3降解其底物,激活AIF,并上调线粒体内Bax/Bcl-2和Bax/Bcl-xL的表达比例诱导A375-S2细胞凋亡。     

PTD4-GFP-VP3融合蛋白在人肝癌细胞HepG2中的定位观察及凋亡诱导效应的实验研究

目的观测PTD4-GFP-VP3融合蛋白诱导人肝癌细胞HepG_2的凋亡效应及其在肿瘤细胞中的定位与其凋亡效应关系的研究。方法构建PTD4-GFP-VP3融合蛋白的原核表达载体,利用人源肝癌细胞株HepG_2,经细胞透膜实验在激光共聚焦显微镜下观察PTD4介导的融合蛋白透膜效应,DAPI染色观测该蛋白在细胞中的定位;利用TUNEL法观察PTIM-GFP-VP3融合蛋白诱导肿瘤细胞的凋亡效应,并利用流式细胞仪检测其凋亡率。结果PTD4-GFP-VP3融合蛋白在孵育细胞0.5h后即可透过细胞膜进入到细胞质中,12h后定位于细胞核并诱导肿瘤细胞凋亡,48h达到最高凋亡效应。结论PTD4能携带GFP-VP3融合蛋白穿透细胞膜,在肿瘤细胞中具有核定位效应,并能诱导肿瘤细胞凋亡,为后期进一步研究VP3的凋亡机制及其抗肿瘤治疗奠定了基础。     

RAS蛋白在胶质瘤中的表达及其对胶质瘤细胞生长的影响

目的 探讨RAS蛋白在胶质瘤中的表达及其对人脑胶质瘤细胞生长的影响.方法 用免疫组化染色法检测RAS蛋白在正常脑组织及各级别胶质瘤组织中的表达水平,并采用四甲基偶氮唑盐微量酶反应比色法和流式细胞技术检测降低RAS活性后U251细胞的增殖和凋亡情况;用Western印迹法检测ERK和AKT信号通路.结果 胶质瘤组织中RAS的表达随胶质瘤恶性程度增高而增强.抑制RAS 蛋白活性后,RAS信号通路的下游分子ERK和AKT蛋白磷酸化水平降低;U251胶质瘤细胞生长受抑制,细胞生长阻滞在G1期且凋亡增加.结论 RAS蛋白在胶质瘤中高表达,抑制其活性可下调ERK和AKT 信号通路,进而调控细胞的生长.     

Isolation of human C-reactive protein and serum amyloid P component

Procedures are described for the isolation in high yield of consistent, highly purified preparations of human C-reactive protein (CRP) and serum amyloid P component (SAP). CRP was obtained from malignant ascitic and pleural fluids by calcium-dependent affinity chromatography on pneumococcal C-polysaccharide covalently coupled to cyanogen bromide-activated Sepharose. It was then gel filtered on Ultrogel AcA44 (acrylamideagarose beads) in the presence of calcium ions, combining molecular sieve chromatography with removal of contaminating SAP by its affinity for agarose. Residual trace contaminants were removed by immunoabsorption with anti-normal human serum and anti-SAP antibodies insolubilised on Sepharose and/or by absorption with Sepharose-Con A to remove glycoproteins and Blue-Sepharose to remove albumin. After a final gel filtration step on Sephacryl S-300 35–44% of the initial CRP was recovered in pure from according to biochemical and immunochemical criteria. SAP was isolated from normal serum by calcium-dependent affinity chromatography on unsubstituted Sepharose beads, followed by solid-phase immunoabsorption of contaminants and finally gel filtration on Sephacryl S-300. At least 50% of the SAP in the starting material was recovered in pure form according to biochemical and immuunochemical criteria. Ready availability of such preparations facilitates biochemical, biophysical and particularly biological studies of these plasma proteins.     

The concentration of the C-type lectin, mannan-binding protein, in human plasma increases during an acute phase response.

Two ELISAs for estimating mannan-binding protein (MBP) were constructed and the concentration of MBP in plasma was followed in patients undergoing major surgery and in patients having a malarial attack. In both cases increases of MBP in the plasma were observed. The relative increase and the kinetics varied from person to person. The concentration of MBP increased between 1.5- and three-fold following surgery. In some patients an increase was seen at day 1 whereas in others the increase was not observed until days 3-9. In the malaria patients an increased level of MBP was maintained during 30 days of treatment with chloroquine. The relative increase in MBP was independent of the presurgery or premalaria levels.     

Lack of binding between cryoimmunoglobulins, immunoglobulins and fibronectin: implications for immune complex vasculitis

Immune-complex-mediated vasculitis is a frequent complication of rheumatoid arthritis and systemic lupus erythematosus. The mechanism of deposition of immune complexes within the vessel wall in these diseases remains unknown, but probably involves other proteins. Fibronectin is a likely candidate since it possesses the ability to bind to collagen, endothelial cells, and possibly immunoglobulins and immune complexes. In this study, the binding of fibronectin to IgG and IgM cryoglobulins, cold soluble IgM, IgG, IgG subclasses and IgG fragments was investigated in the solution phase. Static light scattering, fluorescence anisotropy, fluorescence intensity, and PEG precipitation studies were used to investigate binding under different conditions of temperature and ionic strength. These studies failed to demonstrate significant binding between fibronectin and IgM, IgG, IgG subclasses and IgG fragments under the conditions studied. These findings argue against solution phase binding of fibronectin and immunoglobulins contributing to immune complex vasculitis. The possibility of important surface interactions between these proteins has not been ruled out.     

Binding of mannan-binding protein to various bacterial pathogens of meningitis

Mannan-binding protein (MBP), a calcium-dependent plasma lectin, may play a role in the innate defence against microorganisms. After binding lo carbohydrate structures at the bacterial surface, MBP activates the classical pathway of the complement system. To investigate the binding capacity of MBP to various bacteria associated with meningitis, an assay was developed to study the binding of MBP to bacteria grown in a semisynthetic fluid culture medium. Salmonella montevideo (containing a mannose-rich lipopolysaccharide (EPS)), used as a positive control strain, showed binding of radiolabelled MBP at a level of 80% compared with binding of MBP to zymosan. Binding of labelled MBP to Salm. montevideo was time-dependent, temperature-dependent and saturable. The binding, was inhibited by unlabelled MBP., by mannose and by N-acetyl-o-glucosamine. Among bacterial pathogens often found to cause meningitis, a wide range of MBP binding capacities could be determined. The encapsulated Neisseria meningitidis (representatives from 11 serogroups other than group A were included: n = 22), N. mucosa (n = 1), Haemophilus influenzae type b (n = 10) and Streptococcus agalactiae (n = 5) had a low MBP binding capacity of 21.7% (95% confidence interval (Cl) 3.3–40.1%). Escherichia coli K1 (n =11). Strep, suis (n = 5), Strep, pneumoniae (n = 10) and N. meningitidis scrogroup A (n = 2) showed intermediate MBP binding capacity of 58.4% (95% Cl 40.0–76.8%). A third group consisting of non-encapsulated Listeria monocytogenes (n = 11), non-encapsulated H. influenzae (n = 2), non-encapsulated N. meningitidis (n = 2), N. cinera (n = 1) and N. subflava (n = 1) strains had a high MBP binding capacity of 87.5% (95% CI 62.5–12.5%). The majority of encapsulated pathogens causing bacterial meningitis seem to have a rather low MBP binding capacity.     

β淀粉样蛋白对大鼠学习记忆功能及tau蛋白异常磷酸化的影响

为了探讨β淀粉样蛋白对大鼠学习记忆功能和tau蛋白异常磷酸化的影响,本文在海马注射Aβ25-35建立阿尔茨海黙病(AD)大鼠模型的基础上,通过行为学检测、HE染色、免疫组化和免疫蛋白印迹技术对动物的学习能力、组织的病理改变和tau(pS202)、tau(pT231)和tau-5的表达情况进行了分析。在行为学检测中,Aβ注射组大鼠在穿梭箱实验中的主动回避次数和被动回避次数减少,失败次数增多,而在Morris水迷宫测试中的逃避潜伏期和游泳距离延长。HE染色显示Aβ注射组大鼠海马CA1、CA3、齿状回的神经细胞数目减少;而免疫组化和免疫印迹结果显示注射组tau(pS202)阳性细胞明显增加,tau(pS202)、tau(pT231)和tau-5蛋白表达增加。以上结果提示海马内注射Aβ25-35可引起大鼠学习记忆功能下降,可能与神经细胞减少,tau蛋白异常磷酸化增多有关。     

Eosinophil cationic protein and eosinophil protein X in the nasal lavage of children during the first 4 weeks of life. SPACE Collaborative Study Team

Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) are well established as markers of eosinophil activation. We analyzed ECP and EPX concentrations in nasal lavage fluids (NALF) of 378 neonates during their first 4 weeks of life. Inclusion criteria were a positive history of parental allergy and a positive skin prick test or specific IgE (RAST class > or = 2) against at least one out of a panel of common aeroallergens in one or both parents. Twenty-four infants with no history of parental allergy were used as controls. A volume of 2 ml of 0.9% saline was instilled into each nostril and immediately recovered by a suction device. ECP and EPX were analyzed by radioimmunoassay. In 65 samples of three consecutive lavages, EPX was detected in nine samples (13.8%) in the control group, whereas it was detected in 197/360 samples (54.7%) in the study population. The corresponding figures for ECP were 17/65 (26.2%) in the control group and 173/365 (47.4%) in the study group. Both proteins showed a skewed distribution (median/5-95th percentiles for ECP: 0 microg/l [0-69.4] and EPX: 6.6 microg/l [0-73.2]). The differences between the control group and the study group were statistically significant, regardless of the allergic disease of the parents. In children of allergic parents, activation proteins of the eosinophil granulocyte are released on the nasal mucosal surface in about 50% of the studied population at the age of 4 weeks. This early onset of eosinophil activation in the nasal respiratory epithelium may reflect a genetic predisposition to allergy or early exposure to allergens.     

The Product of ORF III in Cauliflower Mosaic Virus Interacts with the Viral Coat Protein through its C-terminal Proline Rich Domain

Using the yeast two-hybrid system, we show that the ORF III product of cauliflower mosaic virus (pIII) interacts through its C-terminus with the viral coat protein. The last five amino acids of pIII were essential for the interaction and virus infectivity. Deletion of the last three amino acids or the mutation F129A decreased the strength of the interaction by 90%. We further show that pIII is closely associated with virus particles found in the inclusion bodies of infected plants but not in viral particles released from the inclusion bodies by urea treatment.     

La蛋白质家族与肿瘤关系

La蛋白相关家族(La-related proteins,LARPs)包括LARP1、LARP1b、LARP3,(Genuine La)、LARP4a、LARP4b、LARP6和LARP7.LARPs结构包含中度保守的RNA识别模体(RNA recognition motif,RRM)和多个其他结构、运输元件,可定位于不同的亚细胞部位与RNA相互作用,在细胞转录和翻译等方面发挥重要的作用.人LARPs最初是在系统性红斑狼疮和Sjogren's综合征患者的血清内发现的自体抗原,目前随着研究深入普遍认为LARPs作为一种RNA分子伴侣参与RNA代谢能发挥多种生物学功能.此前国内有学者研究验证LARPs能稳定乙型肝炎病毒(hepatitis B virus,HBV)的mRNA,帮助其在肝细胞中复制与翻译,在乙型肝炎进展中具有重要作用.近年发现,LARPs在多种恶性肿瘤如子宫颈癌、乳腺癌、肝癌和前列腺癌等的细胞增殖、分化、迁移、血管形成的调节等方面起重要作用.而恶性肿瘤的发生与演进是由环境与遗传因素相互作用而导致的许多基因突变,实际上基因突变产生的编码蛋白质执行细胞生命活动,因而LARPs在肿瘤中扮演的分子角色将可能在肿瘤的诊断与治疗中提供潜在的新靶点、新策略和新途径.