u-PAR反义核酸载体的构建与高侵袭人前列腺癌细胞PC-3M亚系的转染

目的:为了特异封闭PC-3M高侵袭亚系尿激酶型纤溶酶原激活物受体(u-PAR)的表达,观察其对侵袭能力的抑制效应。方法: 应用RT-PCR获得u-PAR的cDNA片段,反向插入pcDNA3质粒载体中,构建u-PAR反义核酸载体并导入高侵袭亚系中;借助RT-PCR和免疫组化检测转染细胞u-PAR的表达。 结果:u-PAR反义核酸载体转染株的u-PAR mRNA和蛋白质水平明显低于对照组,抑制率分别为53%和73%,同时其体外侵袭能力亦明显降低,抑制率为79%。 结论: u-PAR反义核酸在PC-3M高侵袭亚系中发挥了特异封闭作用,为进一步观察u-PAR反义核酸抑制高侵袭前列腺癌细胞亚系的侵袭效应提供了细胞模型。     

Developmental transition in plasticity properties of differentiating astrocytes: age-related biochemical profile of plasminogen activators in astroglial cultures

Plasminogen activator (PA) is a key enzyme in control of the cascade of extracellular proteolytic activities, proteases that degrade the extracellular components. Mammalian cells produce two molecular forms of PA, the urokinase type (u-PA) and the tissue type (t-PA); the u-PA type enzyme regulates cell migration/invasion and related tissue plasticity events. Thus, these plasticity properties of cells are defined by their PAs' biochemical profiles. The capacity of the differentiating glial cells of the central nervous system (CNS) to express and regulate the two types of PA activities has been examined as a function of cell age in culture. Results of the study suggest that only the immature astrocyte is endowed with these plasticity properties. Differentiating heterogeneous rat glial cells in culture express PA activity. Astroglia were identified as the primary source for the glial PA activity, as no PA activity was detected in the purified oligodendroglia. Cellular PA activity levels of differentiating rat and mouse astroglia are developmentally regulated. The specific activity of PA reached its highest level in rat astroglia at a cell age corresponding to 20-32 postnatal days (P20-P32) and in mouse astroglia at P8-P14; thereafter, this declined (three- to fourfold decrease) within 2 weeks to a low value. At comparable ages (P0-P35), the magnitudes of the PA specific activities of the differentiating rat astroglia and of the developing cerebrum, the tissue from which these cells were purified, were similar. Differentiating rat astroglia produce u-PA and t-PA, the cellular content of both is developmentally regulated, and the u-PA form is only found in the immature cells. u-PA is the predominant form in the immature astrocyte until age P13. Both forms are found in cells at ages P14-P30, and at later stages u-PA disappears while the t-PA type persists as the sole form. After 3 more weeks neither of the PA types was detected. Astroglia express also PA inhibitory activity; the rat astroglial PA inhibitor (PAI) seemed to be identical to PAI-1, one of the known types of PAIs. Stimulation of astroglial proliferation by their subculturing in contrast to Schwann cells did not lead to an increase; rather, beyond a certain cell age (P13) it resulted in a threefold irreversible decline in the PA specific activity of the daughter cells. It has been established that various biochemical properties of CNS mature glia appear on schedule with cell age in culture, thus defining "mature"glia in vitro.(ABSTRACT TRUNCATED AT 400 WORDS)     

原发性高血压患者的纤维蛋白溶解活性变化

目的 观察未经治疗的原发性高血压患者的纤维蛋白溶解活性的变化及临床意义。方法 用发色底物法测定42例原发性高血压患者和40例血压正常者的血浆组织型纤维蛋白溶酶原激活物（t-PA)及其抑制剂（PAI－1）的活性和纤维蛋白溶酶原（Plg)活性。结果 原发性高血压患者血浆t-PA活性明显低于血压正常者,PAI－1和Plg活性明显高于血压正常者。结论 研究结果提示原发性高血压患者确实存在内源性纤溶功能低下。     

EGF对小鼠角质形成细胞中组织型纤溶酶原激活剂表达的调节

目的 探讨小鼠表皮角质形成细胞（KC）中,EGF对组织型纤溶酶原激活剂（tPA)表达的影响。方法 应用免疫组化及原位杂交技术, 结合图像分析,定性及定量检测在EGF作用下的小鼠表皮角质形成细胞中,tPA mRNA/蛋白质的表达。结果 小鼠表皮KC经EGF处理12、24、48、72h后,tPAmRNA/蛋白质的量均增加（P＜0．01）,tPAmRNA的表达的 高峰出现于EGF作用24h时,tPA蛋白质表达的高峰则出现于EGF作用48h时。EGF联合0．5、1．0、1．5mmol/L Ca^2 作用小鼠表皮KC48h,与EGF单独作用小鼠表皮KC48h时,tPAmRNAA／蛋白质的表达,均显著降低（P＜0．001）。结论 小鼠表皮KC中,EGF可以时间依赖方式促进 tPAmRNA／蛋白质的表达,但受Ca^2 浓度的影响。     

米非司酮对大鼠黄体和子宫内膜纤溶酶原激活因子的调节作用

采用纤维蛋白铺盖和放射免疫方法研究了米非司酮(RU486)对培养颗粒细胞及黄体细胞纤溶酶原激活因子(包括组织型tPA和尿激酶型uPA)的作用。结果示RU486能明显拮抗入绒毛膜促性腺激素(hCG)促进颗粒细胞tPA活性及孕酮分泌的作用。RU486和PGF2α能明显促进黄体细胞tPA分泌,但孕酮产生明显被抑制。用组织学培养的方法,结果表明,RU486能刺激妊娠子宫内膜tPA和uPA分泌。这些结果表明RU486的抗生育作用部分能通过PA起到抗排卵、溶黄体及抗早孕的作用。     

肝素对大鼠thy-1肾炎肾小球细胞增生和u-PA／PAI?1表达的影响

目的研究u-PA及其抑制物PAI-1在大鼠thy-1肾炎中的表达及意义,并探讨肝素治疗对其表达的影响。方法应用ABC免疫酶标法及图像分析技术,观察对照组、肾炎组和肝素组动物模型肾小球u-PA和PAI-1的表达情况,并与光镜下肾小球细胞计数作相关性分析。结果肝素组动物在其治疗后7、14、21d时,肾小球细胞数明显减少,与肾炎组比较P值分别小于0.05或0.01肾炎组、肝素组肾小球u-PA和PAI-1的表达均高于对照组;于实验3、7、14和21d时,肾炎组动物的肾小球细胞数增多与u-PA和PAI-1的表达呈正相关(P<0.05或0.01);肝素组于实验3、7d时,肾小球细胞数的减少与PAI-1表达降低有关(P<0.05)。结论大鼠thy-1肾炎的肾小球细胞数增多与其u-PA和PAI-1表达程度呈正相关;肝素治疗可减轻大鼠thy-1肾炎肾小球细胞增生,其作用机制可能与病程早期对肾小球PAI-1表达的抑制有关     

Proteolysis and invasiveness of brain tumors: Role of urokinase-type plasminogen activator receptor

Summary The cellular receptor for urokinase-type plasminogen activator (uPAR) in glioblastoma cell lines has been identified and found to be similar to the uPAR expressed by other tumor cell lines. Increased levels of uPAR have been found in primary malignant brain tumor tissues, especially highly malignant glioblastoma, and, to a lesser degree, in malignant astrocytomas, suggesting that this receptor might be involved in efficient activation of pro-uPA and confinement of uPA activity on the cell surface of invading brain tumors. The cell surface uPARs in gliomas could constitute an optimum environment for the generation and activity of plasmin, which is known to play a crucial role in the dissolution of the extracellular matrix during tumor cell invasion.In situ hybridization studies have shown that uPAR mRNA is expressed abundantly in tumor cells and is consistently present at the invasive edges of malignant gliomas. These results imply that uPAR is involved in plasmincatalyzed proteolysis during glioma invasion and that interference with the uPAuPAR interactions could constitute a novel approach for developing therapeutic strategies to counteract invasion of brain tumors.     

高糖摄入对大鼠糖和脂质代谢及纤溶活性影响

①目的　观察高糖摄入对正常 Ｓｐｒａｇｕｅ Ｄａｗ ｌｅｙ（ Ｓ Ｄ）大鼠糖及胰岛素代谢、脂质代谢和纤溶活性的影响。②方法　将雄性 Ｓ Ｄ 大鼠１６ 只随机分为２ 组,实验组于饮水中添加蔗糖（１２０ｇ／ Ｌ）喂养４２ｄ,对照组给以正常饮水,每７ｄ 定时测量体质量（ Ｂ Ｗ）１ 次,实验最后１ｄ 取血测空腹血糖（ Ｆ Ｂ Ｇ）,空腹血清胰岛素（ Ｉ Ｎ Ｓ）,甘油三酯（ Ｔ Ｇ）,总胆固醇（ Ｔ Ｃ）,高密度脂蛋白胆固醇（ Ｈ Ｄ Ｌ Ｃ）水平及血浆纤溶酶原激活物抑制物１（ Ｐ Ａ Ｉ１）活性等指标。③结果与对照组相比,实验组 Ｆ Ｂ Ｇ,血清 Ｔ Ｇ 水平及血浆 Ｐ Ａ Ｉ１ 活性均升高（ｔ＝ ２．３６～４．７３, Ｐ＜ ０．０５,０．０１）;血清 Ｔ Ｃ及 Ｈ Ｄ Ｌ Ｃ水平两组差异无显著性（ｔ＝ １．３７,０．８４, Ｐ＞ ０．０５）;两组血清 Ｉ Ｎ Ｓ水平虽然差异无显著性（ｔ＝ ０．７７, Ｐ＞０．０５）,但是经协方差分析纠正体质量因素后,实验组与对照组相比存在高胰岛素血症（ Ｆ＝ ５．７４, Ｐ＜ ０．０５）;直线相关分析提示,实验组血清 Ｉ Ｎ Ｓ水平与 Ｂ Ｗ ,血清 Ｔ Ｇ水平及血浆 Ｐ Ａ Ｉ１ 活性呈高度正相关,对照组血清 Ｉ Ｎ Ｓ水平与 Ｂ Ｗ 及     

PAI-2ΔCD突变体的构建及其在大肠杆菌中的表达与纯化

目的构建ＰＡＩ－２ΔＣＤ突变体基因,实现在大肠杆菌中的表达并建立重组人ＰＡＩ－２ΔＣＤ的分离纯化方法。方法用ＰＣＲ扩增ＰＡＩ－２ΔＣＤ基因,经限制性内切酶片段分析及核苷酸序列分析后,突变体基因与原核表达载体ｐＬＹ－４重组并转化蛋白酶缺陷型菌株ＪＦ１１２５。经温度诱导表达,表达产物用ＳＤＳ－ＰＡＧＥ,Ｗｅｓｔｅｒｎ印迹法和纤溶抑制活性测定等方法鉴定。工程菌发酵后,经高压匀浆破菌,用离子交换、疏水性色谱和分子筛进行分离。结果经温度诱导表达,ＳＤＳ－ＰＡＧＥ证实在相应相对分子质量处出现表达条带,约占全菌总蛋白的１５％。Ｗｅｓｔｅｒｎ印迹法证实表达产物具有ＰＡＩ－２免疫原性,溶圈抑制法及翻转板法证实表达产物具有纤溶抑制活性。５Ｌ发酵菌液可得湿菌约１００ｇ,经多步纯化后,每升发酵菌液可得纯度达９７％的ＰＡＩ－２ΔＣＤ约３６ｍｇ,比活性为２８６４０ＡＩＵ／ｍｇ。结论成功构建了ＰＡＩ－２ΔＣＤ突变体,实现了在大肠杆菌中的表达,并成功地分离纯化了重组人ＰＡＩ－２ΔＣＤ蛋白。