肝癌组织浸液尿激酶型和组织型纤溶酶原激活物的检测

一些研究表明体液中的尿激酶型纤溶酶原激活物(urokinasetypeplasminogenactivator,u PA)和尿激酶型纤溶酶原激活物受体 (uokinasetypeplasminogenactivatorreceptor,u PAR )浓度与癌细胞自身分泌和释放的水平及其浸润转移有关 ,而组织型纤溶酶原激活物 (tissueplasminogenactivator,t PA)则与癌组织血管内皮细胞的释放和血管新生有关 ,组织型纤溶酶原激活物抑制剂 (Tissueplasminogenactivatorinhibitor 1,PAI 1)则对t PA和u PA起调控作用 ,同时参与癌细胞的转移等过程[1 ,2 ] 。为探讨癌生长和癌扩散转移及血管新生与上述指标之间的…     

尿激酶型纤溶酶原激活物受体及可溶性尿激酶型纤溶酶原激活物受体与炎症相关的研究进展

尿激酶型纤溶酶原激活物受体（urokinase plasminogen activator receptor,uPAR）与尿激酶型纤溶酶原激活物（urokinase plasminogen activator,uPA）同为纤溶酶原激活系统的主要成员,是一种协调多种信号转导途径的多功能分子,可溶性尿激酶型纤溶酶原激活物受体（soluble urokinase plasminogen activator receptor,suPAR）是其可溶形式。除凝血-纤溶以外,uPAR参与了肿瘤侵袭及炎症等多种疾病过程,而suPAR可能是一种良好的炎性标志物。本文就uPAR及suPAR在炎症中的作用进行简要综述。     

组织型纤溶酶原激活物基因的DNA改组

目的：探索利用DNA改组（DNAshuffling)技术，获得更高活性tPA的可能性。方法：以人，恒河猴及大白鼠tPAcDNA为一组基因，进行tPA的DNA改组（DNAfamily shuffling)。以改组后构建的tPA多样性文库转染CHO细胞并进行克隆和筛选。结果：得到了两株有意义的克隆；t9和t17，其中t9克隆表达的tPA活性略高于人tPA，初步的比活性测定结果表明，活性约提高4倍。t17克隆表达的tPA虽然有88个氨基酸的缺失，但仍表现出与人tPA相同的活性，两株克隆经测序证明，为改组后的基因，其序列以人和恒河猴的tPAcDNA序列为主，少数序列来源于大白鼠tPAcDNA。结论：这一探索性结果将为后续几轮的tPADNA改组探明道路，为最终从改组后tPA多样性基因库中筛选到比较理想的重组体打下基础。     

LPS促进HUVECs表达纤溶酶原激活物抑制物1

目的：观察LPS对脐静脉血管内皮细胞(HUVECs)表达组织纤溶酶原激活物(tPA)和纤溶酶原激活物抑制物1(PAI-1)的影响。 方法： 用生长良好的第2、3代HUVECs进行试验。用cell counting kit-8(CCK-8)测定LPS刺激后细胞活性变化；发色底物法测定LPS组和对照组培养液中tPA, PAI-1活性；RT-PCR检测细胞内tPA和PAI-1 mRNA水平。 结果： 与对照组相比，LPS(10 mg/L)对细胞活性没有明显差异。LPS诱导PAI-1活性在24-72 h显著升高(P<0.05),且显著上调PAI-1 mRNA，24 h达到峰值，以后渐降，72 h达到正常水平。而LPS组与对照组tPA活性与tPA mRNA无明显差异(P>0.05)。 结论： LPS(10 mg/L)可显著上调PAI-1 mRNA转录和分泌而不影响tPA mRNA，结果提示LPS可活化内皮细胞，诱发PAI-1 mRNA表达和蛋白分泌而抑制纤溶系统，这有利于微血栓的形成、血栓稳定,血液凝固和DIC发生。     

组织型纤溶酶原激活物单克隆抗体的研制及其特性鉴定

目的：为应用ｔ ＰＡ单克隆抗体建立ＥＬＩＳＡ法检测ｔ ＰＡ含量以及研究ｔ ＰＡ功能和结构的关系。方法：运用杂交瘤技术成功地研制５株ｔ ＰＡ单克隆抗体，并进行较系统的免疫特性的鉴定。结果：５株单抗特异性高，与ｕ ＰＡ、ＰＬＧ、Ｆｇ、Ｆｂ、ＢＳＡ均无交叉反应；亲合力强１Ｈ４＞３Ｃ１０＞５Ｈ１０＞４Ｅ６＞４Ｃ６；腹水效价５×１０－６～１×１０－７；免疫球蛋白亚类为ＩｇＧ１和ＩｇＧ２ａ；５株单抗中，３Ｃ１０和１Ｈ４可明显抑制ｔ ＰＡ活性，而５Ｈ１０、４Ｅ６、４Ｃ６则对ｔ ＰＡ活性无明显影响。结论：为进一步应用这些单抗作为研究手段提供了基础。     

血清中尿激酶型纤溶酶原激活物在女性乳腺癌诊断中的应用

近年来,在我国京津沪地区,乳腺癌发病率已居于妇女恶性肿瘤首位川.研究表明,癌细胞在浸润转移的过程中存在着细胞外基质(extracellularmatrix,ECM)和基底膜成分被相关蛋白酶溶解的活动,纤溶酶原激活在ECM水解过程中起重要作用.     

人,牛内皮细胞组织型纤溶酶原激活物活性的比较

体外培养人脐静脉及胎牛主动脉内皮细胞,分别从其条件培养液中提取t-PA。实验主要分三步:1)胎牛内皮细胞t-PA的纯化;2)兔抗牛内皮细胞t-PA抗血清的制备及纯化其1gG组分;3)免疫亲和层析、纯化人脐静脉及胎牛主动脉内皮细胞t-PA。结果表明,用微量法免疫动物制备的兔抗牛内皮细胞t-PA抗血清具有较高的滴度与特异性。将该抗血清1gG与人、牛内皮细胞CM交联免疫亲和层析,可获得电泳纯的t-PA,其分子量为65000及67000道尔顿。两者活性比较,胎牛主动脉内皮细胞t-PA活性比人脐静脉内皮细胞t-PA明显增高。     

纤溶酶原激活物抑制剂-1与肥胖

纤 溶系统由纤溶酶原、纤溶酶原激活物 ( plasminogenac tivatorPA)和激活物特异性抑制剂 (plasminogenacti vatorinhibitorPAI)、纤溶酶及纤溶酶抑制物组成 ,其主要功能是通过纤溶酶溶解纤维蛋白而将其从循环系统中清除出去。PAI是纤溶系统活性主要的生理调节物 ,它在体内有多种形式 ,包括内皮细胞型 (PAI 1)、胎盘型 (PAI 2 )、尿型 (PAI 3)和连接蛋白酶 1(proteasenexin 1) ,其中PAI 1在纤溶活性调节中起着重要作用 ,它主要灭活组织型纤溶酶原激活物 (t PA)。PAI 1和t PA之间的平衡对维持纤溶系统正常功能十分重要。临床和流…     

缺血再灌注大鼠视网膜组织型纤溶酶原激活物活性与细胞外基质的相关性

目的：探讨缺血再灌注时大鼠视网膜组织型纤溶酶原激活物（tissue-type plasminogen activator，TPA）活性与视网膜微血管外基质降解的相关性。方法：采用眼压升降法造成视网膜缺血后再灌注。实验组分缺血1～2h再灌注1～2h各组。各组视网膜测试TPA的活性，并用免疫组化法对视网膜微血管外基质作Ⅳ型胶原、层粘连蛋白和纤维粘连蛋白染色。结果：缺血再灌注后，大鼠视网膜TPA的活性随缺血和再灌注时间的延长而显著升高；实验组的Ⅳ型胶原、层粘连蛋白和纤维粘连蛋白阳性染色平均单位面积显著地小于正常对照组，阳性染色呈不连续线状的微血管数显著地多于正常对照组。结论：缺血再灌注可引起视网膜TPA的活性升高，使微血管外基质降解，破坏血-视网膜屏障，导致视网膜结构和功能损伤。     

Endocrinology and Paracrinology: Hormonal regulation of tissue-type plasminogen activator and plasminogen activator inhibitor type-1 in cultured monkey Sertoli cells

Sertoli cells play a central role in the control and maintenanceof spermatogenesis. Isolated Sertoli cells of mouse and rattestes have been shown to secrete plasminogen activator (PA)and a plasminogen activator inhibitor type-1 (PAI-1) in culture.In this study, we have investigated the hormonal regulationof PA and PAI-1 activities in cultured monkey Sertoli cells.Sertoli cells (5x105 cells/well) isolated from infant rhesusmonkey testes were preincubated at 35°C for 16 h in 24-wellplates precoated with poly(D-lysine) (5 µg/cm²) in 0.5ml McCoy's 5a medium containing 5% of fetal calf serum and furtherincubated for 48 h in 0.5 ml serum-free medium with or withoutvarious hormones or other compounds. PA as well as PAI-1 activitiesin the conditioned media were assayed by fibrin overlay andreverse fibrin autography techniques respectively. The Sertolicells in vitro secreted only tissue-type PA (tPA), no detectableamount of urokinase-type PA (uPA) could be observed. MonkeySertoli cells were also capable of secreting PAI-1. Immunocytochemicalstudies indicated that both tPA and PAI-1 positive staininglocalized in the Sertoli cells, spermatids and residual bodiesof the seminiferous epithelium; Northern blot analysis furtherconfirmed the presence of both tPA and PAI-1 mRNA in monkeySertoli cells. Addition of follicle-stimulating hormone (FSH)or cyclic adenosine monophosphate (cAMP) derivatives or cAMP-generatingagents and gonadotrophin-releasing hormone (GnRH) agonist orphorbol ester (PMA) to the cell culture significantly increasedtPA activity. PAI-1 activity in the culture was also enhancedby these reagents except 8-bromo-dibutyryl-cAMP, forskolin and3-isobutyl-1-methylxanthin (MIX) which greatly stimulated tPAactivity, whereas decreased PAI-1 activity, implying that neutralizationof PAI-1 activity by the high level of tPA in the conditionedmedia may occur. These data suggest that increased intracellularsignals which activate protein kinase A (PKA), or protein kinaseC (PKC) can modulate Sertoli cell tPA and PAI-1 activities.The concomitant induction of PA and PAI-1 by the same reagentsin the Sertoli cells may reflect a finely tuned regulatory mechanismin which PAI-1 could limit the excession of the proteolysis.     

Urokinase-type plasminogen activator receptor in gastric cancer: tissue expression and prognostic role

The urokinase-type plasminogen activator (UPA) and its inhibitor PAI-1 are thought to play an important part in gastric cancer (GC) invasion and metastasis. Little is known about the behavior and prognostic impact of the receptor for UPA (UPAR). The aims of the present study were: (1) to measure UPAR, UPA and PAI-1 levels in GC and in non-malignant tissue distant from the tumor (NORM); (2) to evaluate their relationship with histomorphological parameters; and (3) to determine their prognostic value. UPAR, UPA and PAI-1 levels were determined by ELISA in GC and NORM samples from 20 patients with GC undergoing surgery. The GC was also examined in terms of the presence (n=10) or absence (n=10) of metastasis, differentiation (five differentiated, 15 undifferentiated) and histotype. Survival was analysed using life table analysis. UPAR, UPA and PAI-1 were significantly higher in GC vs NORM, in the presence of metastasis (UPAR, UPA) and in undifferentiated GC (UPAR, PAI-1). UPAR significantly correlated with UPA and PAI-1. Low levels of UPAR (P=0.04), UPA (P=0.007) and PAI-1 (P=0.02) were associated with a better survival. Our results demonstrate a sharp increase in UPAR in GC and suggest a prognostic role for it. The concomitant activation of UPAR, UPA and PAI-1 in GC confirm the important role of the plasminogen activator system in the process of invasion and metastasis.     

Elevated tissue type plasminogen activator in human granulosa cells correlates with fertilizing capacity

An increased production of plasminogen activators, able to convertplasminogen into plasmin, has been found in experiments in vivoon rat ovarian granulom cells at the time of ovulation, indicatingan involvement in follicular rupture. The graoulosa cells of49 follicles from 20 patients undergoing in-vitro fertilizationwere obtained by laparclscopy and tested for the content ofurokinase-type plasminogen activator (u-PA), tissue-type plasminogenactivator (t-PA) and inhibitor of plasmhogen activator (PAI).In the respective follicular fluids the concentrations of oestradiol(E₂), progesterone (P) and testosterone (T) were determinedand the levels of these enzymes and of the follicular steroidcontent were related to the fertilizing behaviour of the respectiveoacytes. Follicles containing oocytes which could be fertilized,revealed significantly higher follicular fluid E₂ and P levelsand significantly lower T levels than follicles with unfertilizedoocytes. The respective granulosa cells of fertilized oocytesexhibited higher levels of t-PA compared to their unfertilizedcounterparts, whereas no significant difference occurred inthe levels of u-PA and PAI. These data suggest that successfulfertilization of human oocytes is associated with a high contentof t-PA in granulom cells and high E₂ and P levels in the follicularfluid.     

The use of PEGylated liposomes to prolong circulation lifetimes of tissue plasminogen activator

Tissue plasminogen activator (tPA), a widely used thrombolytic agent, has an application limit due to short half-life. To prolong the half-life of tPA, liposomes composed of egg phosphatidylcholine (EPC), cholesterol (CHOL) and sodium cholesterol-3-sulfate (CS) were prepared by lipid film method. In addition, distearolyphosphatidyl ethanolamine-N-poly(ethylene glycol) 2000 (DSPE–PEG 2000) was included to give steric barrier to liposomes. Physicochemical characteristics such as particle size, zeta potential, entrapment efficiency and long-term storage stability at 4 °C were investigated. The fibrinolytic activity of tPA-loaded in liposomes was confirmed by fibrin clot lysis assay. In vivo pharmacokinetic properties of tPA and the effect of PEG on the blood circulation of tPA-loaded in liposomes in circulation were also evaluated. Both conventional liposomes (EPCL) and PEGylated liposomes (EPC–PEGL) were proper as an injectable formulation with small particle size. Loading process of tPA into liposomes did not alter fibrinolytic activity of intact tPA. Encapsulation of tPA into EPCL and EPC–PEGL prolonged half-life of tPA by 16 and 21 folds compared with free tPA, respectively. Therefore, the use of liposomes could prolong the circulation lifetimes and longevity effect of liposomes on tPA was increased by PEG.     

登革2型病毒调控血管内皮细胞纤溶系统相关蛋白的表达

目的观察登革2型病毒（DV2）对人脐静脉血管内皮细胞（HUVEC）表达组织纤溶酶原激活物（tPA）和纤溶酶原激活物抑制物1（PAI-1）的影响。方法应用胰酶消化分离HUVEC并进行传代培养，用生长良好的第2．3代细胞进行试验。用cell counting kit-8（CCK-8）测定DV2感染后细胞活性变化；发色底物法测定感染DV2组和对照组培养液中tPA、PAI-1活性；RT-PCR检测细胞内tPA和PAI-1 mRNA水平。结果DV2感染对细胞活力的影响与对照组相比差异无统计学意义。感染DV2组培养液中tPA活性在12～72h显著升高（P〈0．05）；DV2诱导HUVEC表达tPA mRNA的水平显著上调，12h达到峰值，以后渐降，72h mRNA表达水平仍高于对照组（P〈0．01）。而DV2感染组培养液中PAI-1活性和PAI-1 mRNA的表达与对照组比较差异无统计学意义（P〉0．05）。结论DV2感染可显著上调HUVEC的tPA mRNA转录，增强内皮细胞tPA蛋白的分泌，而不影响PAI-1 mRNA的转录或改变内皮细胞PAI-1的分泌。结果提示DV2可活化但并不损伤内皮细胞，诱发内皮细胞增强表达纤溶酶原激活物而致使纤溶系统失衡，引起纤溶亢进，这可能是诱发DHF／DSS患者急性期出血、低血容量性休克等体征的主要因素之一。     

Tissue-type plasminogen activator and its inhibitor in human glomerulonephritis.

We carried out an immunohistochemical study of tissue-type plasminogen activator (PA) and urokinase-type PA, and their inhibitors, PA inhibitor-1 and PA inhibitor-2, using renal biopsy specimens obtained from 86 patients with various forms of glomerulonephritis. The controls were four normal renal tissue specimens. On immunofluorescent observation, granular staining for tissue-type PA was found to be distributed along the glomerular capillary walls. The fluorescence was weak in the normal renal tissue and occasionally intense in the tissues of patients with IgA nephritis, minimal change nephrotic syndrome, and lupus nephritis. PA inhibitor-1 was abundant in the glomerular epithelial cells and scarce in the mesangial area and glomerular capillary lumens of the normal renal tissues. This was confirmed by immunoelectron microscopy using gold staining. The fluorescence of PA inhibitor-1 was weaker in some specimens of nephritic tissues than in the normal renal tissues. Urokinase-type PA and PA inhibitor-2 were negative within the glomeruli in all the specimens. In the glomerulonephritic tissues which were fibrin deposition-positive, tissue-type PA expression in the glomeruli tended to be strong. An association between fibrin deposition and PA inhibitor-1 staining was not clear. These data suggest that expression of tissue-type PA in the glomeruli increases in association with fibrin deposition.     

缺血性脑卒中治疗时间窗后辅助溶栓治疗的进展

组织纤溶酶原激活物（tPA）溶栓是缺血性脑卒中治疗的金标准,然而,tPA的治疗时间窗和超过治疗时间窗后再应用所致的致命性副作用限制其的临床应用。为了解决tPA应用的限制性,可联合应用tPA与其他药物或非药物的介入方式治疗,且部分联合治疗方案经实验验证可以减轻治疗时间窗外应用tPA所致并发症,尤其是出血性转化（HT）。联合应用药物的作用机制包括保护血脑屏障,增强血管生成作用和保护脑血管。非药物介入方式则包括干细胞移植和有多方面生物效应的气体治疗。tPA与上述治疗方式的联合应用旨在减轻滞后tPA治疗所致的副作用和脑卒中所诱发的神经性缺损和行为损伤。因此,辅助治疗是一种创新的治疗形式,可解决tPA治疗的限制因素,并可能延长缺血性脑卒中的治疗时间窗。     

Inhibition of B16BL6 melanoma invasion by tyrosine and phenylalanine deprivation is associated with decreased secretion of plasminogen activators and increased plasminogen activator inhibitors

We previously found that dietary tyrosine (Tyr) and phenylalanine (Phe) limitation significantly decreased the metastatic phenotype of B16BL6 melanoma cells in vivo and decreased the in vitro invasion of these cells. To more specifically characterize the effects of Tyr and Phe deprivation we examined the three steps involved in invasion: attachment to host cells and components, elaboration of proteases that degrade basement membranes, and migration of invading tumor cells. Here we report that B16BL6 melanoma cell invasion through growth factor reduced (GFR) Matrigel^TM is significantly decreased by Tyr and Phe deprivation. Tyr and Phe deprivation in vitro decreased the attachment of B16BL6 melanoma cells to GFR Matrigel^TM, heparin sulfate proteoglycans (HSPG), neonatal murine epidermal (NME) cells and the extracellular matrix (ECM) from these cells. These cells also exhibited a decrease in chemotactic response to fetal bovine serum (FBS). Deprivation of these two amino acids decreased the secretion of urokinase plasminogen activator (uPA) and tissue plasminogen activator (tPA) while plasminogen activator inhibitor (PAI)-1 and -2 were increased in these cells. These observations suggest that Tyr and Phe deprivation decreases the in vitro chemotactic and invasive ability of B16BL6 melanoma cells by decreasing attachment and secreted PA activity and by increasing secreted PAIs in these cells. This revised version was published online in July 2006 with corrections to the Cover Date.