组织型纤溶酶原激活物在周围神经损伤修复中的作用及其研究进展

纤溶酶原激活物(plasminogen activators,PAs)是一类丝氨酸蛋白酶,包括组织型纤溶酶原激活物(tissue PA,tPA)和尿激酶型纤溶酶原激活物(urokinase PA,uPA)两种类型,主要作用是催化纤溶酶原转变为有活性的纤溶酶.     

纤溶酶原激活物及其抑制剂与肾脏疾病

纤溶酶原激活物（PA）及其抑制剂（PAI）是调节纤溶系统活性的重要物质,肾脏固有细胞可合成PA和PAI－1,PA／PAI平衡对维持细胞外基质的合成与降解平衡十分重要,本文就PA／API－1在肾脏的合成,分布及其生理功能,肾脏疾病中外周血,肾组织PA／API和尿PA变化及其病理意义进行综述。     

纤溶酶原激活物及其抑制剂与肾脏疾病

纤溶酶原激活物 (PA)及其抑制剂 (PAI)是调节纤溶系统活性的重要物质。肾脏固有细胞可合成PA和PAI 1 ,PA/PAI平衡对维持细胞外基质的合成与降解平衡十分重要。本文就PA/PAI 1在肾脏的合成、分布及其生理功能 ,肾脏疾病中外周血、肾组织PA/PAI和尿PA变化及其病理意义进行综述。     

7/8肾切除大鼠凝血纤溶系统的变化及干预治疗的影响

目的：探讨肾小球硬化及小管间质纤维化过程中肾组织纤溶酶原激活物（PA）和PA抑制物（PAI）－1蛋白表达及干预治疗的影响。方法：7／8肾切除肾功能衰竭大鼠为实验动物模型,随机分为未治疗组和治疗组,观察12周后各组大鼠血尿各项生化指标、尿PA活性及残肾组织常规病理和用免疫组织化学染色定性定量评价残肾组织型PA（tPA)、尿激酶型（uPA)、PAI－1蛋白表达。结果：未治疗组大鼠肾功能进行性丧失,尿PA活性下降,肾组织PAI－1表达增高,而tPA、uPA表达下降,残肾组织出现肾小球硬化和间质纤维化。治疗组大鼠残肾组织tPA、uPA蛋白表达增加,PAI－1表达下降。尿PA活性增加,肾功能改善。结论：水蛭治疗组、苯那普利治疗组及联合治疗组都可以通过改善7／8肾切除大鼠PA／PAI－1系统的紊乱而延缓肾小球硬化和间质纤维化病变的进展。     

洛伐他汀对高糖时人肾小管上皮细胞核因子—kB和组织纤溶酶原激活物及其抑制物的作用

目的：观察高糖环境中,肾小管上皮细胞组织纤溶酶原激活物（tPA）及其抑制物－1（PAI－1）异常与核因子（NF）－kB激活的关系,并探讨洛伐他汀对其改善作用。方法：体外培养人肾小管上皮细胞（HKC）,用高糖刺激HKC细胞,并与洛伐他汀共孵育。发色底物法检测细胞上清中PAI－1和tPA活性;RT－PCR方法观察HKC细胞合成PAI－1和tPA mRNA表达;共聚焦显微镜和免疫印迹法检测核转录因子NF－kB的作用。结果：高糖可激活NF－kB(p65),并使HKC细胞培养上清中PAI－1活性和mRNA表达增加,tPA活性和mRNA表达降低;洛伐他汀可以部分或全部逆转高糖的作用。结论：高糖促使HKC细胞PAI－1和tPA异常表达,可能与NF－kB激活有关。洛伐他汀可以通过非降脂的甲羟戊酸途径逆转高糖对HKC细胞NF-kB和PAI－1与tPA的影响。     

慢性前列腺炎对纤溶酶原激活因子系统影响的初步研究

目的 :分析慢性前列腺炎对纤溶酶原激活因子 (PA)系统表达和活性的影响。　方法 :选取正常男性 2 3例 ,慢性前列腺炎患者 80例 (不育组和可生育组各 4 0例 )。采用纤维蛋白 琼脂糖PA指示胶打孔法和SDS PAGE电泳后指示胶铺盖法 ,测定精浆中总PA及组织型纤溶酶原激活因子 (tPA)和尿激酶型纤溶酶原激活因子 (uPA)的表达和活性。结果 :在正常人精浆中有高表达的总PA活性 ;而且同时表达tPA和uPA。慢性前列腺炎患者的精浆中总PA活性降低 ,tPA活性明显减低 ,uPA活性减低。慢性前列腺炎的可生育组和不育组精浆中总PA活性均降低 ,但两组间无明显差别。　结论 :患慢性前列腺炎时前列腺分泌功能降低 ,合成分泌PA减低。PA有可能在今后作为临床中判断前列腺功能检测指标之一     

组织纤溶酶原激活物和纤溶酶原激活物抑制剂-1与腹腔镜手术的关系

组织纤溶酶原激活物(t-PA)和纤溶酶原激活物抑制剂-1(PA I-1)是纤溶系统的重要组成部分,传统开腹手术,t-PA与PA I-1之间的平衡被打破,导致术后腹腔粘连及血栓形成。腹腔镜手术对人体创伤小,对腹膜刺激少,因此,对t-PA和PA I-1之间的平衡影响减小,术后粘连及血栓形成的发生率及程度也随之降低。本文综述了t-PA和PA I-1与腹腔镜手术方面的研究进展。     

纤维蛋白溶酶原激活物抑制物1的研究进展

纤维蛋白溶酶原激活物抑制物(plasminogen activator in-hibitor,PAI)是纤维蛋白溶解系统的重要组成成分,是纤维蛋白溶酶原活化系统的特异性快速抑制物,是体内纤溶活性重要的调节剂.PAI主要存在于血小板、肝细胞、平滑肌细胞等组织细胞内,在很多生理学和病理学过程中发挥着重要作用,如纤维蛋白溶解、细胞外基质(extracellular matrix,ECM)循环、纤维形成、伤口愈合和癌症转移等过程[1].     

兔角膜碱烧伤后早期尿激酶型纤溶酶原激活剂及其受体的表达

作为纤溶酶原激活剂／纤溶酶原激活剂抑制剂(plasminogen activator／plasminogen activator inhibitor，PA／PAI)级联的重要因子，尿激酶型纤溶酶原激活剂(urokinase type PA，uPA)及其受体uPA-R具有高效的分解细胞外环境蛋白酶的作用。研究表明，uPA和uPA-R在角质形成细胞的迁移、增殖、分化以及重建上皮组织等方面发挥着十分重要的作用，但有关它们在角膜碱烧伤中的作用鲜见报道。本实验对兔角膜碱烧伤后早期uPA和uPA-R的表达进行了研究。     

组织纤溶酶原激活物和纤溶酶原激活物抑制剂-1与腹腔镜手术的关系

组织纤溶酶原激活物（t-PA）和纤溶酶原激活物抑制剂-1（PAI-1）是纤溶系统的重要组成部分,传统开腹手术,t-PA与PAI-1之间的平衡被打破,导致术后腹腔粘连及血栓形成.腹腔镜手术对人体创伤小,对腹膜刺激少,因此,对t-PA和PAI-1之间的平衡影响减小,术后粘连及血栓形成的发生率及程度也随之降低.本文综述了t-PA和PAI-1与腹腔镜手术方面的研究进展.     

Regulation of plasminogen activator and plasminogen activator inhibitor production by growth factors and cytokines in rat calvarial cells

Summary Fetal rat osteoblast-enriched calvarial cells were used to study the effects of various growth factors and cytokines on plasminogen activator (PA) and plasminogen activator inhibitor (PAI) activities and the possible relationship of these effects to bone resorption. Confluent cultures were exposed to various factors under serum-free conditions, and levels of PA and PAI activities were examined in both conditioned medium (CM) and cell layer using the¹²⁵I-fibrin plate assay, fibrin zymogram, and reverse fibrin zymogram. According to the¹²⁵I-fibrin plate assay or zymogram, incubation of cells with acidic fibroblast growth factor (aFGF), basic FGF (bFGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF) elevated the PA activity in the CM as well as in the cell layer extract. Incubation with interleukin 1α (IL-1α), tumor necrosis factor α (TNFα), and insulin-like growth factor I (IGF-I) produced no change in PA activity in either CM or cell layer. Addition of transforming growth factor β (TGFβ) to calvarial cells resulted in nearly undetectable PA activity in CM with the fibrin plate assay but increased PA activity on the fibrin zymogram after PAI was separated from PA by SDS-PAGE. A reverse fibrin zymogram indicated that PAI activity was greatly enhanced in TGFβ-treated CM. TGFβ treatment also increased PA activity in the cell layer of calvarial cells. Treatment of calvarial cells with bFGF and PDGF slightly increased PAI secretion into medium. This increase, however, was not as dramatic as the increase of PA induced by these two agents. IL-1α and TNFα did not change PAI concentration in CM. No detectable PAI activity was found in the cell layer in control and treated groups. The PA found in the CM and cell layer of rat calvarial cells was the urokinase type; the PAI stimulated by TGFβ was the endothelial cell type, PAI-1. The regulation of PA activity by growth factors and cytokines did not correlate with their resorption-stimulating activities. Thus, PA secreted by osteoblasts may not be the only factor involved in the initiation of bone resorption. Delineation of the function of PA and PAI in the physiology of bone tissue awaits further studies.     

纤溶酶原激活物抑制物1与肝细胞癌

目的研究纤溶酶原激活物抑制物１（ＰＡＩ１）在肝细胞癌（ＨＣＣ）蛋白和ｍＲＮＡ水平的表达及其与ＨＣＣ生物学特性的关系。方法取ＨＣＣ石蜡标本４８例,肝良性肿瘤石蜡标本１２例（对照组）做免疫组化染色;液氮冻存ＨＣＣ标本２０例,肝血管瘤５例（对照组）做免疫印迹杂交。结果肝癌细胞与癌周细胞及对照组肝细胞相比,ＰＡＩ１抗原蛋白和ｍＲＮＡ表达显著升高,差异有显著意义,Ｐ值分别＜００１和＜０．０５。术后２年内死亡病例与生存病例相比,ＰＡＩ１阳性率有显著意义的升高,Ｐ＜００５。ＰＡＩ１和纤溶酶原激活物（ｕＰＡ）及其受体（ｕＰＡＲ）同时阳性患者与同时阴性患者相比,前者侵袭性病例较后者升高有显著性意义（Ｐ＜００５）。结论ＨＣＣ中ＰＡＩ１蛋白和ｍＲＮＡ表达明显增高。ＰＡＩ１与ＨＣＣ浸润转移和预后密切相关。     

IL-8-stimulated expression of urokinase-type plasminogen activator in human skin and human epidermal cells

Extracellular matrix (ECM) remodeling is essential for normal development and tissue repair. Although many roles for extracellular proteinases in the breakdown of ECM have been established, the regulations of these proteinases in human tissue are not fully understood. Inflammatory cytokines have been implicated in the regulation of several matrix metalloproteinases. To determine whether these mediators have a similar effect on fibrinolysis and the remodeling of the fibrin provisional matrix, we examined the role of cytokines on the regulation of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) in human skin. In this report, we show that interleukin-8 (IL-8), but not other cytokines tested, is a potent inducer of the 38-kDa uPA in organ-cultured human skin. In addition, the uPA inhibitor, PAI-1, was not affected by IL-8. When primary epidermal human keratinocytes were treated with IL-8, 55-kDa pro-uPA was significantly induced in the conditioned medium. The mRNA expression of uPA in the keratinocytes was found to be constitutively elevated and was not affected by IL-8. To support such a notion, activation of the 5'-flanking promoter of the human uPA gene was measured using the CAT reporter assay. Consistent with the results of mRNA measurement, the promoter is constitutively active in keratinocytes and is not affected by IL-8. In contrast, the promoter construct is neither active in the dermal fibroblasts nor stimulated by the cytokine. This differential transactivation of uPA gene in these cells indicates that keratinocyte-specific factors may govern the basal expression of the gene. These results indicate a complex regulation of uPA expression in epidermal cells.     

人正常胚胎和葡萄胎绒毛中纤蛋白溶酶原激活与抑制因子及其尿激酶受体的表达

本研究应用原位杂交技术检测人正常胚胎及葡萄胎绒毛中纤蛋白溶酶原激活与抑制因子（ｔＰＡ,ｕＰＡ,ＰＡＩ－１）及其尿激酶受体（ｕＰＡ－Ｒ）的表达。结果表明,人正常胚胎绒毛的合体滋养层和细胞滋养层细胞中均含有ｔＰＡ、ｕＰＡ、ＰＡＩ－１及ｕＰＡ－ＲｍＲＮＡ,葡萄胎绒毛中ｔＰＡ、ＰＡＩ－１及ｕＰＡ－ＲｍＲＮＡ表达明显增强。提示：（１）ＰＡ－ＰＡＩ的协同作用在维持妊娠期间正常的纤蛋白溶解可能是重要的;（２）纤溶激活与抑制在葡萄胎的发展过程中可能起作用     

Increased bone formation in mice lacking plasminogen activators.

Plasminogen activators tPA and uPA are involved in tissue remodeling, but their role in bone growth is undefined. Mice lacking tPA and uPA show increased bone formation and bone mass. The noncollagenous components of bone matrix are also increased, probably from defective degradation. This study underlines the importance of controlled bone matrix remodeling for normal endochondral ossification. INTRODUCTION: Proteolytic pathways are suggested to play a role in endochondral ossification. To elucidate the involvement of the plasminogen activators tPA and uPA in this process, we characterized the long bone phenotype in mice deficient in both tPA and uPA (tPA-/-:uPA-/-). MATERIALS AND METHODS: Bones of 2- to 7-day-old tPA-/-:uPA-/- and wild-type (WT) mice were studied using bone histomorphometry, electron microscopy analysis, and biochemical assessment of bone matrix components. Cell-mediated degradation of metabolically labeled bone matrix, osteoblast proliferation, and osteoblast differentiation, both at the gene and protein level, were studied in vitro using cells derived from both genotypes. RESULTS: Deficiency of the plasminogen activators led to elongation of the bones and to increased bone mass (25% more trabecular bone in the proximal tibial metaphysis), without altering the morphology of the growth plate. In addition, the composition of bone matrix was modified in plasminogen activator deficient mice, because an increased amount of proteoglycans (2x), osteocalcin (+45%), and fibronectin (+36%) was detected. Matrix degradation assays showed that plasminogen activators, by generating plasmin, participate in osteoblast-mediated degradation of the noncollagenous components of bone matrix. In addition, proliferation of primary osteoblasts derived from plasminogen activator-deficient mice was increased by 35%. Finally, osteoblast differentiation and formation of a mineralized bone matrix were enhanced in osteoblast cultures derived from tPA-/-:uPA-/- mice. CONCLUSIONS: The data presented indicate the importance of the plasminogen system in degradation of the noncollagenous components of bone matrix and suggest that the accumulation of these proteins in bone matrix--as occurs during plasminogen activator deficiency--may in turn stimulate osteoblast function, resulting in increased bone formation.     

The role of the plasminogen system in bone resorption in vitro.

The plasminogen/plasmin proteolytic cascade plays an important role in extracellular matrix remodeling. The presence of the two plasminogen activators (PAs), tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA), and their inhibitor type 1 (PAI-1) in bone cells, suggests a role in one or more aspects of bone resorption such as osteoclast formation, mineral dissolution, and degradation of the organic matrix. These different processes were assayed in vitro using cells derived from mice with either tPA (tPA-/-), uPA (uPA-/-), PAI-1 (PAI-1-/-) inactivation or with a combined inactivation (tPA-/-:uPA-/-) and compared with wild-type mice (WT). First, osteoclast formation, assessed by investigating the number and characteristics of tartrate-resistant acid phosphatase-positive multinucleated cells formed in cocultures of primary osteoblasts and bone marrow cells treated with 1alpha,25-dihydroxyvitamin D3, was not different between the different cell types. Second, dentine resorption, an assay for osteoclast activity, was not affected by the combined deficiency of both tPA and uPA. Finally, the ability to degrade nonmineralized bone-like matrix was however, significantly reduced in tPA-/-:uPA-/- cells compared with WT cells (28.1 +/- 0.6%, n = 6 vs. 56.4 +/- 3.1%, n = 6, respectively, p < 0.0001). Surprisingly, collagen proteolysis by bone cells was not dependent on the presence of plasmin as suggested by degradation assays performed on type I 3H-collagen films. Taken together, these data suggest that the plasminogen activator/plasmin system is not required for osteoclast formation, nor for the resorption of the mineral phase, but is involved in the removal of noncollagenous proteins present in the nonmineralized bone matrix.     

Cartilage synthesizes the serine protease inhibitor PAI-1: support for the involvement of serine proteases in cartilage remodeling

The work described here demonstrates the synthesis by human articular cartilage of plasminogen activator inhibitor-1 (PAI-1), a potent inhibitor of the serine protease tissue plasminogen activator (tPA). We also present data demonstrating an increase in PAI-1 messenger ribonucleic acid (mRNA) in chondrocytes exposed to the cytokine interleukin-1 (IL-1). Interestingly, this elevation of steady-state mRNA levels does not appear to result in an increase in synthesis of PAI-1 protein. Northern blot analysis reveals that of the two mRNA species (3.4 kb, 2.4 kb) previously reported for PAI-1, only the larger species (3.4 kb) appears to be synthesized by chondrocytes. Our data demonstrate the IL-1-stimulated production by cartilage of tissue plasminogen activator. We also show evidence for the presence of plasminogen in cartilage. A scheme is presented indicating the probable importance of the serine proteases (tPA and plasminogen) and PAI-1 in cartilage degradation.     

Human seminal fibrinolytic activity: specific determinations of tissue plasminogen activator and urokinase

The determination of total fibrinolytic activity of ejaculates was realized by fibrin plate method. For the same seminal samples, tissue plasminogen activator (t-PA), urinary plasminogen activator (uPA) antigens and uPA activity were specifically quantified. The seminal values were fifty times higher than in the blood for t-PA and fifteen times for uPA. There was no correlation between the both levels but from split ejaculates measurements a higher concentration was observed in all first fractions. By zymography assays, it was shown that seminal plasminogen activators are under active forms. The lack of proUrokinase in semen was also demonstrated.     

Nipple Aspirate Fluid Expression of Urokinase-Type Plasminogen Activator,Plasminogen Activator Inhibitor-1, and Urokinase-Type Plasminogen Activator Receptor Predicts Breast Cancer Diagnosis and Advanced Disease

Background: Tumor expression of urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and uPA receptor (uPAR) are breast cancer prognostic factors. Less is known about their usefulness in breast cancer diagnosis. Nipple aspirate fluid (NAF) is secreted into the breast duct and collected noninvasively, making it potentially useful both in breast cancer diagnosis and prognosis. We determined the association of uPA, PAI-1, and uPAR levels in NAF with breast cancer (1) detection and (2) advanced disease.Methods: A total of 88 NAF specimens were collected from women with or without breast cancer, and uPA, PAI-1, and uPAR expression were measured by enzyme-linked immunosorbent assay.Results: uPA and uPAR were independent predictors of cancer presence; uPAR was also an independent predictor of advanced disease stage. Higher PAI-1 expression in breast cancer that was found with univariate analysis was not observed after logistic regression was applied.Conclusions: NAF evaluation of uPA, uPAR, and, perhaps, PAI-1 (significant only in univariate analysis) may provide useful breast cancer diagnostic and prognostic information.