Study on the Mechanism of the Annexin I -Mediated Co-Assembly of t-PA and Plasminogen

In order to further investigate the effect of annexin Ⅱ (Ann- Ⅱ ) on tissue plasminogen activator (t-PA)-dependent plasminogen (PLG) activation and its interactive mechanism, recombinant native Ann- Ⅱ bound t-PA, PLG and plasmin with high affinity was examined. The flow cytometric assay showed that the ann- Ⅱ expression rate was higher in the human umbilical vein endothelial cell (HUVEC) (87. 65 %) than in the HL-60 cells as controls (35. 79 %). Two irrelevant proteins,bovine serum albumin (BSA) and equine IgG (EIG) had no effect on the production of plasmin.Ann- Ⅱ -mediated enhancement of t-PA-dependent PLG activation was inhibited by ε-aminocaproic acid or by pretreatment of Ann- Ⅱ with carboxypeptidase B with the inhibitive rate being 77.8 % and 77. 0 %, respectively. It was revealed that the effect of Ann- Ⅱ on PLG activation was specific for tPA. Urokinase didn‘t bind to Ann- Ⅱ , demonstrating the role of receptor-related lysine residues on activation of PLG, showing that the Ann- Ⅱ -PLG interaction was dependent upon carboxyl-terminal lysine residues. These findings suggest that annexin Ⅱ -mediated co-assembly of t-PA and PLG may promote plasmin generation and play a key role in modulating fibrinolysis on the endothelial surface.     

MicroRNA-34a inhibits human brain glioma cell growth by down-regulation of notch1

The effects of microRNA-34a (miR-34a)-regulated Notch1 gene on the proliferation and apoptosis of the human glioma cell line U87 were investigated in this study. The U87 cells were divided into miR-34a mimics, negative control, mock transfection and blank control groups in terms of different treatments. In miR-34a mimics group, human U87 glioma cells were transfected with miR-34a mimics by using lipofectamine 2000. The cells transfected with nonsense microRNA were set up as negative control group. Those treated with lipofectamine 2000 only were designated to the mock tranfection group. In the blank control group, the cells were cultured routinely and no treatment was given. The expression of miR-34a and Notch1 was detected by using real-time RT-PCR. Western blotting was employed to monitor the change in Notch1 protein. Cell proliferation and apoptosis were measured by CCK-8 and flow cytometry. The results showed that the proliferative ability of U87 cells was significantly reduced and the apoptotic cells increased in miR-34a mimics group relative to control groups. The expression of miR-34a was significantly up-regulated in mimics group as compared with control groups (P<0.05). Furthermore, Notch1 protein levels were significantly decreased in miR-34a mimics group when compared with control groups (P<0.05), but the mRNA expression of Notch1 showed no significant difference among these groups. It was concluded that miR-34a may suppress the proliferation and induce apoptosis of U87 cells by decreasing the expression of target gene Notch1, suggesting that miR-34a may become a promising gene therapeutic target for brain glioma.     

EXPRESSION AND ROLE OF PLASMINOGEN SYSTEM IN PROCESS OF RESTENOSIS

Objective To study the expression and role of plasminogen system in the process of restenosis. Methods We established a double-injury model of atherosclerotic restenosis in rabbit iliac artery mimicking human arterial restenosis. The time course of tissue plaminogen activator （ tPA ）, urokinase plasminogen activator （ uPA ）, urokinase plasminogen activator receptor （uPAR） and plasminogen activator inhibitor-1 （ PAI-1 ） was investigated by immunohistochemistry. The mRNA expression of uPA and uPAR were detected after vascular procedures by in situ hybridization. Results In uninjured arteries, the weak expression of tPA and PAI-1 was detected in intimal and endothelial cells. The expression of tPA, uPA, uPAR and PAI-1 was significantly induced after double-injury, but after double-injury 14d, the expression of tPA restore to preinjury levels. The expression of uPA and uPAR in intimal was higher than that of media and maintain high levels in intimal within 42d and 56d. Conclusion Whereas t-PA is primarily involved in clot dissolution and play a limited role in the process of restenosis, in plasminogen system, uPA and uPAR play a prominent role in the process of restenosis.     

Inhibitory Effects of Anti-sense PTTG on Malignant Phenotype of Human Ovarian Carcinoma Cell Line SK-OV-3

To construct eukaryotic expression vector expressing full length anti-sense pituitary tumor transforming gene (PTTG) mRNA and observe its blocking effect on the potential invasion of human ovarian carcinoma cell line SK-OV-3. PCR primers containing designed enzyme cut sites were used for cloning full-length PTTG gene fragment, and the resulting PCR product was inserted into the eukaryotic vector pcDNA3. 1 in the antisense direction. The recombinant vector was then transfected into SK-OV-3 by Lipofectamine. The positive cell clone was screened by G418, PTTG and bFGF at protein level expression were detected by Western blot. The biological behavior change of transfection positive cells was observed by colony formation in soft agar assay. Our results showed that SK-OV-3 clones stably expressing full-length recombinant pcDNA3. 1-PTTGas were obtained. The expressions of PTTG and bFGF protein in transfected cells were decreased by 61.5% and 52.3%, respectively as compared with non-transfected ones. The number of colony formation was reduced significantly in transfected cells as compared with empty vector transfected and non-transfected cells. It is concluded that the recombinant vector pcDNA3. 1-PTTGas is a novel tool and provides an alternative anti-sense gene therapy targeted at PTTG in human carcinoma.     

Role of protein kinase C in advanced glycation end products-induced epithelial-mesenchymal transition in renal proximal tubular epithelial cells

The role of protein kinase C （PKC） activation in advanced glycation end products （AGEs）-induced epithelial-mesenchymal transition in renal proximal tubular epithelial cells was investigated. HKC cells were divided into three groups： normal group, AGE-BSA group （100 mg/L AGE-BSA） and AGE-BSA＋PKC inhibitor （10 μmol/L chelerythrine chloride） group. PKC activity was measured by PKC assay kit. The expression of Vimentin, and phosphorylated β-catenin was detected by using Western blotting, and the content of TGF-β1 was examined by ELISA method. The intracellular disposition of Vimentin was observed by fluorescence microscopy. As compared with normal group, PKC activity was increased significantly in AGE-BSA group. The expression of Vimentin, phosphorylated β-catenin, and TGF-β1 was enhanced significantly in AGE-BSA group. The expression of Vimentin, phosphorylated β-catenin, and TGF-β1 was significantly blocked by chelerythrine chloride. High expression of Vimentin, phosphorylated β-catenin, and TGF-β1 induced by AGE-BSA may be mediated via the activation of PKC signal transduction pathway.     

Serum Hormone and Cellular Proliferation Changes of Testis in Rats with Experimental Orchitis Induced by Lipopolysaccharide

Objective To explore the changes of serum male hormone, androgen binding protein (ABP) expression as well as the proliferation of testicular cells in rats with experimen- tal orchitis induced by bacterial lipoplysaccharide (LPS) in vivo and to elucidate the putative mechanism of LPS on spermatogenesis of testis. Methods The serum testosterone (T), luteinizing hormone (LH) levels were detected with magnetic enzyme immunoassay. The expression of proliferating cell nuclear antigen (PCNA) and ABP expression at mRNA level of testis were studied with immuno- histochemical staining and in situ hybrydization respectively. Results The serum T level in rats with experimental orchitis was significantly higher than that in the rats of control (P<0.05) and ABP mRNA expression in Sertoli cells of testis was significantly increased (P<0.05) while PCNA expression in seminiferous epithelium in experimental rats significantly was decreased as compared with that of the control (P<0.05). No significant change in serum LH level was seen between ex- perimental orchitis and control groups (P>0.05). Conclusion The serum level of T and ABP expression significantly increased in rats with experimental aspecific orchitis induced by LPS, and at the same time inhibition of cellular proliferation of seminiferous epithelium can be detected, which may be the possible mechanism of male infertility in inflammatory process.     

Reversal of Multidrug Resistance and Inhibition of Phosphorylation of AKT in Human Ovarian Cancer Cell Line by Wild-type PTEN Gene

The reversing effect of wild-type PTEN gene on resistance of C13K cells to cisplatin and its inhibitory effect on the phosphorylation of protein kinase B (AKT) were studied. The expression of PTEN mRNA and protein in OV2008 cells and C13K cells were semi-quantitatively detected by using RT-PCR and Western blotting. Recombinant eukaryotic expression plasmid containing human wild-type PTEN gene was transfected into C13K cells by lipofectamine2000. The expression of PTEN mRNA was monitored by RT-PCR and the expression of PTEN, Akt, p-Akt protein were ana- lyzed by Western blotting in PTEN-transfected and non-transfected C13K cells. Proliferation and chemosensitivity of cells to DDP were measured by MTT, and cell apoptosis was detected by flow cytometry after treatment with cisplatin. The expression of PTEN mRNA and protein in OV2008 cells were significantly higher than those in C13K cells. After transfection with PTEN gene for 48 h, the expression of PTEN mRNA and protein in C13K cells were 2.04±0.10, 0.94±0.04 respectively and the expression of p-Akt protein ( 0.94±0.07) was lower than those in control groups (1.68±0.14, 1.66±0.10) (P< 0.05). The IC50 of DDP to C13K cells transfected with PTEN (7.2±0.3 μmol/L) was obviously lower than those of empty-vector transfected cells and non-transfected cells (12.7±0.4 μmol/l, 13.0±0.3 μmol/L) (P<0.05). The apopototis ratio of wild-type PTEN-transfected, empty vector transfected and non-transfected C13K cells were (41.65±0.87)%, (18.61±0.70)% and (15.28 ±0.80)% respectively, and the difference was statistically significant (P<0.05). PTEN gene plays an important role in ovarian cancer multidrug resistance. Transfection of PTEN could increase the ex- pression of PTEN and restore drug sensitivity to cisplatin in human ovarian cancer cell line C13K with multidrug-resistance by decreasing the expression of p-Akt.     

Effect of Smac on TRAIL-induced apoptosis of prostate cancer cell line PC-3 and the molecular mechanism

The effect of Smac gene on the TRAIL-induced apoptosis of the prostate cancer cell line PC-3 and the molecular mechanism were investigated. The Smac gene was transfected into PC-3 cells under the induction of liposome. The intrinsic Smac gene expression was detected by Western blotting. After treatment with TRAIL as an apoptosis inducer, in vitro cell growth activity was as-sayed by MTT colorimetry. The apoptosis rate of PC-3 cells was determined by annexin Ⅴ-FITC and propidium iodide staining flow cytometry. The expression of cellular XIAP and caspase-3 genes was examined by Western blotting. Smac-transfected cells (PC-3/Smac group) had significantly in-creased Smac protein level as compared with PC-3 controls (P<0.01). After induction with 100-200 ng/mL TRAIL for 12-36 h, cellular proliferation rate in PC-3/Smac group was significantly lower than in PC-3 controls (P<0.05). After induction with 100 ng/mL TRAIL for 24 h, the apoptosis rate in PC-3/Smac group was significantly enhanced as compared with that of PC-3 controls (P<0.05). Ac-cordingly, the XIAP expression level was down-regulated significantly (P<0.05) and caspase-3 sub-unit P20 was up-regulated significantly (P<0.05). It is suggested that the over-expression of cellular Smac can inhibit inhibitor of apoptosis proteins (IAPs), enhance caspases activity and the apoptosis rate of PC-3 cells induced by TRAIL, which may provide a useful experimental basis for prostate cancer therapy.     

Study on the mechanism of the annexin II-mediated Co-assembly of t-PA and plasminogen

In order to further investigate the effect of annexin II (Ann-II) on tissue plasminogen activator (t-PA)-dependent plasminogen (PLG) activation and its interactive mechanism, recombinant native Ann-II bound t-PA, PLG and plasmin with high affinity was examined. The flow cytometric assay showed that the ann-II expression rate was higher in the human umbilical vein endothelial cell (HUVEC) (87.65%) than in the HL-60 cells as controls (35.79%). Two irrelevant proteins, bovine serum albumin (BSA) and equine IgG (EIG) had no effect on the production of plasmin. Ann-II-mediated enhancement of t-PA-dependent PLG activation was inhibited by epsilon-aminocaproic acid or by pretreatment of Ann-II with carboxypeptidase B with the inhibitive rate being 77.8% and 77.0%, respectively. It was revealed that the effect of Ann-II on PLG activation was specific for t-PA. Urokinase didn't bind to Ann-II, demonstrating the role of receptor-related lysine residues on activation of PLG, showing that the Ann-II-PLG interaction was dependent upon carboxyl-terminal lysine residues. These findings suggest that annexin II-mediated co-assembly of t-PA and PLG may promote plasmin generation and play a key role in modulating fibrinolysis on the endothelial surface.     

妇科恶性肿瘤患者术后血液血栓前状态的检测

目的：探讨妇科恶性肿瘤患者血栓前状态生物指标的变化。方法：检测38例妇科恶性肿瘤患者手术前后及20例正常非孕妇女的血管性血友病因子（vWF)、血小板α－颗粒膜蛋白（GMP－140）、抗凝血酶（AT－Ⅲ）、蛋白C依赖的活化部分凝血酶原时间（PCAT）、纤溶酶原（PLG）、纤溶酶原激活物抑制物（PAI）、D－二聚体和组织纤溶酶原激活物（t-PA)等指标。结果：妇科恶性肿瘤患者术前vWF含量、GMP－140、AT－Ⅲ、PLG、PAI、D－二聚体均比对照组高（P＜0．01），而术后升高更明显；PCAT手术前、后均明显低于正常非孕妇女；而组织纤溶酶原激活物（t-PA) 则无显著性改变（P＞0．05）。结论：提示妇科恶性肿瘤患者术前血液呈血栓前状态，术后呈更明显的血栓前状态。     

Coagulation and fibrinolytic activity in patients with acute cerebral infarction

Thecoagulationandfibrinolyticactivityinpatientswithacutecerebralinfarctionisabnormal Toinvestigatetheirchanges ,wemeasuredtheconcentrationofD dimer (DD) ,tissueplasminogenactivator (t PA) ,plasminogenactivitorinhibitor 1(PAI 1)andplaminogen (PLG )activityinplasmaandcerebrospinalfluid METHODSSubjectswererandomlyselectedfrom 35consecutiveischemicstrokepatients (2 1menand 14womenwithameanageof 6 3years)admittedtoourhospitalwithin 72hoursafteronsetfromApril 2 0 0 0toFebruary 2 0 0 1 Ofthes…     

妊娠晚期糖尿病孕妇止凝血功能指标检测的临床意义

目的 探讨妊娠晚期糖尿病孕妇的血小板活化状态、血管内皮损伤、抗凝及纤溶系统部分功能指标的变化及其临床意义.方法 检测了正常非孕妇女、正常晚期妊娠妇女各20例和46例妊娠晚期糖尿病孕妇的血管性血友病因子、血小板α-颗粒膜蛋白、抗凝血酶-Ⅲ、蛋白C系统筛选、纤溶酶原、组织纤溶酶原激活物及其抑制物、D-二聚体等指标的含量.结果 与正常非孕组及正常晚期妊娠组比较,妊娠晚期糖尿病孕妇组血管性血友病因子、血小板α-颗粒膜蛋白、组织纤溶酶原抑制物水平均显著增高(P＜0.01),组织纤溶酶原激活物活性明显低于正常晚期妊娠组(P＜0.01);与正常非孕组比较,正常晚期妊娠组和妊娠期糖尿病组空腹血糖、纤溶酶原、D-二聚体等指标均显著增高(P＜0.01).与正常晚期妊娠组比较,妊娠期糖尿病组空腹血糖、纤溶酶原、D-二聚体均显著增高(P＜0.01),抗凝血酶-Ⅲ、蛋白C活性依赖凝固时间在正常晚期妊娠组较非孕组呈下降趋势,妊娠期糖尿病患者AT-Ⅲ水平与正常晚期妊娠组无显著差异.结论 正常晚期妊娠妇女血液处于血栓前状态,而糖尿病孕妇存在着明显的血栓前状态,因此,糖尿病孕妇产前测定凝血和纤溶功能指标,对监测病情、指导治疗、改善预后具有一定的价值.     

脑血栓患者纤溶活性的动态观察

目的　测定脑血栓患者治疗前后纤溶活性的变化 ,探讨其发病机制及诊治方案。　方法　分别采用发色底物法定量检测纤溶酶原 (PLG)、组织纤溶酶原激活物 (t-PA)以及纤溶酶原激活抑制物 (PAI)的活性 ,并用双抗体夹心法测定D -二聚体 (D -D)。　结果　脑血栓患者治疗前t -PA活性较低 ,PLG、PAI活性较高 ,D -D含量增多 ,与正常对照组比较 ,均有显著性差异 (P <0 .0 5 )。治疗后 ,患者t-PA活性增强 ,PLG、PAI活性减弱 ,与治疗前比较 ,差异有显著性 (P <0 .0 5 )。D -D水平与治疗前比较差异无显著性 ,但有升高趋势。　结论　脑血栓患者病程中纤溶系统存在着动态变化 ,测定其纤溶活性的变化 ,将有助于诊治。     

急性高眼压t-PA表达的实验研究

目的:探索血浆组织型纤溶酶原活化因子(t-PA)在青光眼视网膜中的表达变化、可能的作用以及脑源性神经营养因子(BDNF)对其的影响。方法:采用前房灌注法建立兔急性高眼压模型,在玻璃体内注射BDNF或BSS液,用免疫组织化学法检测视网膜t-PA的蛋白表达与定位,用Westernblot分析检测视网膜t-PA的蛋白表达。结果:t-PA与β-actin灰度比值,正常对照组为(57.95±3.79)%、BSS组为(89.36±3.59)%、BDNF组为(66.66±2.16)%;BSS组与正常对照组和BDNF组相比,t-PA表达明显升高(P<0.05)。高眼压后视网膜上t-PA的免疫组化染色明显增强,神经纤维层、RGCs层呈强阳性染色。结论:t-PA与青光眼的病理过程有相关性,BDNF可能部分通过抑制t-PA的表达发挥神经元保护作用。     

肝病患者手术及介入治疗后凝血纤溶指标监测对疗效的评估作用

目的探讨肝病患者手术或介入治疗后凝血及纤溶指标的变化对疗效的评估价值。方法对肝病组（100例）、肝癌组（100例）于手术或介入治疗前与后检测血浆凝血酶原时间（PT）、活化部分凝血酶原时间（AFTT）、纤维蛋白原（FIB）、抗凝血酶Ⅲ（ATⅢ）活性、蛋白C（PC）活性、蛋白S（PS）活性、纤溶酶原（PLG）活性、组织型纤溶酶原活化物（t-PA）、纤溶酶原活化剂抑制物（PAI）、α2-抗纤溶酶（α-PI）活性、纤溶酶-纤溶酶抑制物（PAP）,并与正常对照组100例比较。结果与对照组比较,肝癌组介入治疗前与后PT、APT、t-PA、PAI、PAP均明显升高（P〈0．05或〈0．01）,FIB、ATⅢ活性、PC活性、PS活性、PLG活性、α2-PI活性均明显降低（P〈0．05或〈0．01）;与介入治疗前比较,介入治疗后PT、APTT、t-PA降低,FIB、ATⅢ活性、PC活性、PS活性、PLG活性、α2-PI活性升高（P〈0．05）,而PAI-1和PAP均差异无统计学意义（P〉0．05）。与对照组比较,肝病组手术治疗前与后PT、APTT、t-PA、PAP均明显升高（P〈0．05或〈0．01）,而FIB、ATⅢ、PC活性、PS活性、PLG活性、PAI、α2-PI活性降低（P〈0．01）;与手术治疗前比较,肝病组手术治疗后PT、APTT、t-PA、PAP降低（P〈0．05或〈0．01）,FIB、ATⅢ活性、PC活性、PS活性、PLG活性、PAI、α2-PI活性升高（P〈0．05或〈0．01）。结论肝病组和肝癌组均存在抗凝活性降低及易发纤溶。手术或介入治疗后有所改善,但未完全恢复正常。     

TNF-α对人脐静脉内皮细胞t-pA、pAI-1表达的研究

目的：观察肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）对人脐静脉内皮细胞（HUVECs）组织型纤溶酶原激活物（tissue plasminogen activitor,t-PA）及其抑制剂-1（plasminogen activitor inhibitor-1,PAI-1）表达的影响。方法：原代分离HUVECs细胞并进行传代培养,分别以6个TNF-α浓度组（0、1、10、20、50、100 ng·m L-1）处理不同时间（0、1、3、6、12、24 h）,酶联免疫吸附分析（ELISA）法测定t-PA、PAI-1抗原的表达;逆转-聚合酶链反应（RTPCR）检测t-PA、PAI-1基因的表达。结果：TNF-α促进PAI-1抗原的表达,并呈剂量和时间依赖关系,在TNF-α10 ng·m L-1作用6 h时最明显（P〈0.01）;TNF-α促进PAI-1 mRNA的表达,并呈剂量和时间依赖关系,在TNF-α10 ng·m L-1作用3 h时已非常明显（P〈0.01）,6 h时达到高峰（P〈0.01）;而TNF-α对HUVECs表达t-PA抗原、mRNA无明显影响。结论：炎症因子TNF-α可能通过上调PAI-1表达而诱发血栓相关疾病。     

Activity of Ginkgo biloba extract and quercetin on thrombomodulin expression and tissue-type plasminogen activator secretion by human umbilical vein endothelial cells

INTRODUCTION Ginkgo biloba extract (GBE) has been used as a ommonly prescribed drug in traditional Chinese edicine for several thousand years. GBE is still sed in clinics in Europe to alleviate symptoms ssociated with blood circulation disorder. It has be…