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。     

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。     

睾酮对人血管内皮细胞纤溶活性影响及机制

目的：观察睾酮对人血管内皮细胞分泌纤溶酶原激活物（tPA）、纤溶酶原激活物抑制物1（PAI-1）的影响及其机制。方法： 将体外培养的人血管内皮细胞（HUVEC）分为5个浓度睾酮组及单纯培养基对照组，MTT实验观察睾酮对细胞生长及活性影响。ELISA 法测各组tPA、 PAI-1含量。用雄激素受体拮抗剂(flutamide)预处理细胞后重复实验。结果： 生理及略低于生理剂量睾酮（3×10-10 mol/L-3×10-8 mol/L）可明显促进tPA 分泌（P＜0.01）；而大剂量则使tPA 含量明显减少（P＜0.01）。各睾酮组PAI-1含量均明显低于对照组（P＜0.05）。Flutamide 能有效消除睾酮的上述作用。结论： 生理浓度睾酮通过雄激素受体促进tPA分泌，降低PAI-1浓度而增强纤溶系统活性，有利于防止血栓性疾病的发生。     

体外培养的血管内皮细胞低氧低糖损伤后tPA、PAI-1表达变化

目的：观察体外培养的血管内皮细胞低氧低糖损伤后组织型纤溶酶原激活剂(tPA)、Ⅰ型纤溶酶原激活物抑制因子(PAI-1)表达变化，探讨脑缺血后纤溶系统的变化及机制。材料和方法：制备体外内皮细胞低氧低糖损伤模型，利用HE染色、免疫细胞化学染色观察tPA、PAI-1表达变化。结果：低氧低糖损伤后，tPA、PAI-1表达均明显增强。结论：成功制备体外内皮细胞低氧低糖损伤模型。内皮细胞低氧低糖损伤可以诱导tPA、PAI-1表达增多，进一步说明脑缺血损伤后tPA、PAI-1表达增加并参与损伤过程。     

同型半胱氨酸和叶酸对内皮细胞tPA合成及其mRNA表达的影响

目的探讨同型半胱氨酸(Hcy)及叶酸对内皮细胞纤溶系统的作用,观察Hcy和叶酸对人脐静脉血管内皮细胞(HUVEC)组织型纤溶酶原激活物(tPA)含量及其mRNA表达的影响. 方法将体外培养的HUVEC分为10个实验组0、10、50、200、500μmol/L 浓度Hcy组及叶酸(15μmol/L)和上述各Hcy共同培养组,培养24*!h后,酶联免疫吸附实验法(ELISA)测定各组细胞上清液中的tPA含量,反转录聚合酶链反应(RT-PCR)半定量分析各组tPA mRNA表达水平. 结果与单纯培养基组(0μmol/L Hcy)相比,10μmol/L Hcy组(生理浓度组)tPA 含量及mRNA表达明显增高(P<0.05).超生理剂量Hcy时,tPA含量及mRNA表达剂量依赖性地下降,但与对照组差异无显著性(P>0.05).而与生理浓度Hcy相比,当Hcy浓度达到500μmol/L时,tPA合成及mRNA表达水平均明显减少(P<0.05).加入叶酸后,可以减弱Hcy抑制tPA合成及mRNA表达的作用,500μmol/L Hcy共同培养组与单纯Hcy组相比具有统计学意义(P<0.05). 结论高Hcy可下调tPA 的mRNA表达,减少内皮细胞tPA的分泌,可能降低纤溶系统的活性.叶酸则可减少高Hcy引起内皮细胞纤溶系统的损害,起到保护作用.生理浓度的Hcy可上调tPA 的mRNA表达,增加内皮细胞tPA的分泌,可能提高纤溶系统的活性.     

辛伐他汀对尼古丁诱导脐静脉 内皮细胞分泌t-PA和PAI-1的影响

目的: 研究不同浓度辛伐他汀对尼古丁诱导人脐静脉内皮细胞(HUVECs)分泌组织纤溶酶原激活物(t-PA)和1型纤溶酶原激活物抑制剂(PAI-1)及其基因表达的影响。方法: 将3-6代体外培养的HUVECs随机分为对照组、尼古丁组及不同浓度辛伐他汀组,辛伐他汀组分别以1、10、100 μmol/L辛伐他汀预处理细胞2 h,再以100 μmol/L尼古丁孵育24 h。酶联免疫吸附双抗体夹心法(ELISA)检测细胞上清液t-PA和PAI-1含量;逆转录聚合酶链反应(RT-PCR)检测细胞t-PA和PAI-1 mRNA的表达。结果: 尼古丁组PAI-1分泌和mRNA表达较对照组显著升高(P<0.05)。不同浓度辛伐他汀组PAI-1分泌和mRNA表达均较尼古丁组显著降低,且PAI-1分泌和mRNA表达的降低呈浓度依赖性(均P<0.05),以100 μmol/L辛伐他汀组最为显著。100 μmol/L辛伐他汀组PAI-1分泌和mRNA表达与对照组比较,无显著差异(P>0.05)。尼古丁组t-PA mRNA表达较对照组显著降低(P<0.05)。10、100 μmol/L辛伐他汀组t-PA mRNA表达较尼古丁组显著升高(P<0.05),各组间t-PA分泌无显著差异(均P>0.05)。结论: 在体外,辛伐他汀可降低尼古丁所致的PAI-1分泌和mRNA的表达,并升高t-PA mRNA的表达,从而逆转尼古丁介导的HUVECs纤溶活性减低。     

尼古丁对血管内皮细胞释放t-PA及PAI-1的影响

目的: 研究尼古丁对人脐静脉内皮细胞(HUVECs)释放组织型纤溶酶原激活物(t-PA)和纤溶酶原激活物抑制物-1(PAI-1)的影响。方法: HUVECs培养后接种于24孔培养板中,随机分为对照组及实验组,分别进行以下实验。(1)以0.1、1、10、100 μmol/L 尼古丁孵育HUVECs,12 h后收集各组上清液;(2)以100 μmol/L尼古丁与HUVECs孵育0、4、6、8、12 及24 h,收集各组上清液。采用ELISA法测定各组t-PA和PAI-1的浓度。结果: HUVECs与不同浓度尼古丁孵育12 h后,100 μmol/L尼古丁组PAI-1蛋白较对照组明显增加(P<0.01);0.1、1及10 μmol/L尼古丁组PAI-1蛋白与对照组比较,均无显著差异(均P>0.05);各浓度组t-PA蛋白与对照组比较,均无显著差异(均P>0.05)。HUVECs 与100 μmol/L的尼古丁分别孵育4 、6 、8 、12 及24 h,各组PAI-1蛋白均较对照组明显升高(P<0.05),且其升高呈时间依赖性;各组t-PA与对照组比较,均无显著差异(均P>0.05)。结论: 尼古丁可抑制HUVECs的纤溶活性,对内皮细胞具有损伤作用。     

新生大鼠缺氧缺血性脑损伤tPA、PAI-1表达的动态变化

目的:观察新生大鼠缺氧缺血性脑损伤(HIBD)中组织型纤溶酶原激活物(tPA)和1型纤溶酶原激活物抑制剂(PAI-1)表达变化的规律,探讨纤溶系统在缺氧缺血性脑损伤中的作用。方法:7日龄SD新生大鼠96只,随机分为2组:缺氧缺血性脑损伤组和假手术组。两组动物模型制备成功后3、6、12、24、36、48、72、96小时断头取脑,应用免疫组织化学及原位杂交方法检测缺氧缺血性脑损伤不同时间点t-PA、PAI-1表达的变化。结果:假手术组新生大鼠各脑区均有tPA、PAI-1蛋白及mRNA的弱表达,缺氧缺血性脑损伤组不同时间点t-PA、PAI-1二者表达呈不同的动态变化:tPA蛋白及mRNA 3小时开始表达增强,主要见于皮质和海马,神经元表达明显,血管表达较弱,48小时神经元及微血管内皮表达明显增强,72小时神经元表达明显减弱,微血管内皮见有明显阳性表达,之后表达减弱,3～96小时各时间点阳性着色神经元数目显著高于假手术组;PAI-1蛋白及mRNA 12小时表达有所增强,神经元和微血管内皮表达增多,72小时达高峰,12～96小时各时间点阳性着色神经元数目显著高于假手术组。结论:tPA和PAI-1参与HIBD的发病机制。     

CRRT治疗MODS患者血清对体外培养血管内皮细胞分泌TF及PAI-1的影响

目的: 研究连续性肾脏替代治疗(CRRT)过程中多器官功能障碍综合征(MODS)患者血清对体外培养血管内皮细胞分泌组织因子(TF)及纤溶酶原激活物抑制剂-1(PAI-1)的影响.方法: 16例MODS患者随机分为两组, 一组给予无肝素CRRT治疗, 另一组给予普通肝素抗凝的CRRT治疗.观察患者行CRRT治疗8h过程中的变化, 在治疗0 min、 15 min、 1 h、 2 h、 8 h时分别留取血样5 mL.ELISA法检测患者血清TNF-α、 IL-1β水平.观察CRRT治疗不同时间点血清对内皮细胞分泌TF及PAI-1蛋白水平的影响, RT-PCR法检测TF及PAI-1mRNA水平的表达.结果: MODS患者血清可明显增加体外培养血管内皮细胞TF及PAI-1的分泌, 经CRRT治疗后, 患者血清对内皮细胞分泌TF及PAI-1的影响逐步减小.无肝素组内皮细胞分泌TF及PAI-1蛋白水平与相应干预血清TNFα水平均呈正相关, 相关系数分别为0.902, 0.939(P＜0.05);肝素组内皮细胞分泌TF及PAI-1水平与相应干预血清TNFα水平均无相关性(P＞0.05).结论: MODS患者血清促进内皮细胞分泌TF及PAI-1, 内皮细胞功能明显异常, 可能与炎症介质有关.CRRT治疗可清除血液中激活/损伤内皮细胞的成分, 改善患者内皮细胞功能.     

慢性肾脏疾病血清和尿液纤溶活性物质的改变及临床意义

目的探讨慢性肾脏疾病血清和尿液纤溶活性物质的改变及其临床意义。方法选择38例慢性肾小球肾炎(CGN),28例肾病综合征(NS),36例非透析治疗的慢性肾功能不全(CRF)和20例正常对照作为研究对象,应用ELISA法检测血清和尿液中组织型纤溶酶原激活剂(t-PA)和纤溶酶原激活物抑制剂-1(PAI-1)的浓度,同时分析尿中t-PA和PAI-1的水平与血t-PA、PAI-1、血肌酐和24h尿蛋白总量之间相关性。结果慢性肾脏疾病出现血清t-PA、PAI-1升高,尿液t-PA、PAI-1降低,其中尿液t-PA、PAI-1的改变独立于血清,不受血肌酐和24h尿蛋白定量的影响。结论慢性肾脏疾病患者存在纤溶活性物质的异常,其中尿液纤溶活性物质的改变可反应肾脏内皮细胞损伤。     

Increased release of tissue plasminogen activator and its inhibitor in human parotid saliva upon stimulation.

Parotid saliva from 12 healthy volunteers was collected prior to and after 5 and 25 min of stimulation at a constant flow rate of 0.25 or 1.0 ml min-1. In the salivary samples the concentrations of tPA (tissue-type plasminogen activator), PAI-1 (plasminogen activator inhibitor type-1), albumin and total protein were determined and the activity of amylase, tPA and PAI assessed. Presence of both tPA and PAI-1 antigen was demonstrated in all samples, and in unstimulated saliva the ratio between the activator and its inhibitor was 1:7. Upon stimulation we found a significantly increased concentration of PAI-1, a less pronounced increase in tPA concentration, unchanged amylase and total protein levels and significantly decreased albumin concentration. tPA activity was significantly reduced after prolonged stimulation which had no effect on PAI activity. In stimulated saliva a significant positive correlation between concentration of tPA and PAI-1 was demonstrated. Stimulation with citric acid had no effect on output of albumin which is passively filtered from blood, whereas the increase in flow rate corresponded to the significantly increased secretion rate of total protein and amylase which is secreted by gland cells. The secretion pattern of tPA and PAI-1 differed significantly from that of albumin in showing markedly increased output rate during the stimulation period, and the relative increase in output of PAI-1 was significantly higher than that of amylase and total protein. Thus, the results from this study suggest an active release of both tPA and its main inhibitor PAI-1 into saliva.     

Increased release of tissue plasminogen activator and its inhibitor in human parotid saliva upon stimulation

Parotid saliva from 12 healthy volunteers was collected prior to and after 5 and 25 min of stimulation at a constant flow rate of 0.25 or 1.0 ml min^-1. In the salivary samples the concentrations of tPA (tissue-type plasminogen activator), PAI-1 (plasminogen activator inhibitor type-1), albumin and total protein were determined and the activity of amylase, tPA and PAI assessed. Presence of both tPA and PAI-1 antigen was demonstrated in all samples, and in unstimulated saliva the ratio between the activator and its inhibitor was 1:7. Upon stimulation we found a significantly increased concentration of PAI-1, a less pronounced increase in tPA concentration, unchanged amylase and total protein levels and significantly decreased albumin concentration. tPA activity was significantly reduced after prolonged stimulation which had no effect on PAI activity. In stimulated saliva a significant positive correlation between concentration of tPA and PAI-1 was demonstrated. Stimulation with citric acid had no effect on output of albumin which is passively filtered from blood, whereas the increase in flow rate corresponded to the significantly increased secretion rate of total protein and amylase which is secreted by gland cells. The secretion pattern of tPA and PAI-1 differed significantly from that of albumin in showing markedly increased output rate during the stimulation period, and the relative increase in output of PAI-1 was significantly higher than that of amylase and total protein. Thus, the results from this study suggest an active release of both tPA and its main inhibitor PAI-1 into saliva.     

Diabetic nephropathy and plasminogen activator inhibitor 1 in urine samples

Plasminogen activator inhibitor-1 (PAI-1) may contribute to renal fibrosis because of its involvement in matrix (ECM) accumulation through inhibition of plasmin-dependent ECM degradation. The aim of this study is to determine urinary PAI-1 concentrations and its intrarenal localization in patients with various renal diseases and to identify inducers for PAI-1 expression in human cultured proximal renal tubular cells (HRCs). Urinary PAI-1 concentrations were significantly higher in patients with overt diabetic nephropathy (DN, n=36) than in proliferative glomerulonephritis (PGN, n=8), nephrotic syndrome (NS, n=10) and healthy controls (n=12). Urinary PAI-1 concentrations (ng/gCr) were directly correlated with urinary N-acetyl glucosaminidase (NAG) levels (r=0.58, p<0.05). As for intrarenal localization of PAI-1 antigen, strong stainings for PAI-1 were observed in proximal tubular cells of renal biopsy samples from patients with DN, while no stainings for PAI-1 were found in renal tissues of PGN or NS. Immunoblot analysis revealed the presence of PAI-1 protein in whole cell lyzates from HRCs grown to semiconfluency. Exposure of growth-arrested HRCs with hypoxia (1% O2) or TNF-alpha (10 ng/ml) for 24 hours increased the secretion rate of PAI-1 protein by about 2.0-fold, while 24-hour treatment with high glucose (450 mg/dl) did not increase PAI-1 secretion at all, compared with that of the control cells under normal glucose (100 mg/dl) and normoxia (18% O2). These findings suggest that PAI-1 expression is upregulated especially in the proximal renal tubular cells of DN, which may be explained partially by hypoxia and inflammatory cytokines but not high glucose.     

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. plasminogen activator inhibitor type-1/Rhesus monkey/Sertoli cells/tissue-type plasminogen activator     

胰岛α细胞培养上清液对INS-1细胞胰岛素释放与合成的影响

在培养的INS 1细胞中 ,分别加入不同比例的胰岛α细胞培养上清液 (以下简称上清液 ) ,在不同浓度葡萄糖的刺激下 ,分别孵育不同时间 ,用放射免疫法测定INS 1细胞培养基中的胰岛素含量。在 2 0mmol L葡萄糖浓度下 ,不同刺激时间 ,不同浓度的上清液刺激INS 1细胞分泌的胰岛素显著高于 0 %上清液 (以下简称对照组 ,P <0 0 5或0 0 1 )。在 0、1 85mmol L葡萄糖刺激时 ,不同浓度的上清液对INS 1细胞的胰岛素分泌无明显作用 ,而在 5 6、1 6 7和 5 0mmol L葡萄糖刺激时 ,不同浓度的上清液刺激INS 1细胞分泌的胰岛素显著高于对照组 (P <0 0 5或 0 0 1 )。RT PCR结果显示 ,在 1 6 7mmol L葡萄糖刺激 4、1 2和 2 4h后 ,30 %上清液对INS 1细胞胰岛素mRNA水平均无明显影响。提示胰岛α细胞培养上清液对糖刺激的INS 1细胞的胰岛素分泌有促进作用 ,但不影响胰岛素的生物合成