Plasminogen activator system, vascular endothelial growth factor, and colorectal cancer progression.

AIMS: To plasminogen activator system (PAS) consists of the plasminogen activators (urokinase (uPA) and tissue-type (tPA) plasminogen activators), the uPA receptor (uPAR), and the plasminogen activator inhibitors (PAI-1 and PAI-2). Plasminogen activators activate plasminogen to plasmin, which can break down extracellular matrix (ECM) components. Vascular endothelial growth factor (VEGF) is a mitogen for endothelial cells and is involved in angiogenesis. VEGF has been shown to upregulate uPA and this may facilitate tumour angiogenesis further. METHODS: PAS components and VEGF were determined by enzyme linked immunosorbent assay (ELISA) in paired colorectal tumour and normal tissue (n = 50) and correlated with pathological staging. RESULTS: uPA, uPAR, PAI-1, and VEGF values were significantly higher in tumour tissue (for example, tumour uPA: median, 2.3 (range, 0.1-6.7) ng/mg protein v normal uPA: median, 0.2 (range, 0-2.6) ng/mg protein). tPA was significantly higher in normal mucosa and there was no difference in PAI-2. uPA, uPAR, PAI-1, and VEGF values significantly correlated with each other and with Dukes's staging (uPA in adenomas: median, 0.42 (range, 0.1-1.2) ng/mg protein; upA in Dukes's B tumours: median, 2.1 (range, 0.4-4.3) ng/mg protein; and uPA in Dukes's D tumours: median, 4.0 (range, 3.7-4.2) ng/mg protein) and lymphatic invasion. In addition PAI-1 also correlated with tumour size and differentiation. CONCLUSION: The involvement of the PAS and VEGF in colorectal cancer appears to be complex. uPA, uPAR, PAI-1, and VEGF were upregulated in tumour tissue and this correlated with Dukes's staging and lymphatic invasion.     

uPA和PAI-1在人脑胶质瘤的表达及其与肿瘤血管生成的关系

目的探讨uPA、PAI鄄1和VEGF与人脑胶质瘤病理分级和侵袭行为的关系及各因子间的相互联系。方法采用免疫组化SP方法检测42例人脑胶质瘤和8例正常脑组织uPA、PAI鄄1和VEGF蛋白的表达。结果12例中低度恶性胶质瘤中,uPA、PAI鄄1和VEGF阳性表达率分别为58.3%、50.0%、33.3%,30例高度恶性胶质瘤的阳性率分别为96.7%、86.7%、93.3%,两组间各指标相比较,uPA和VEGF差异有极显著性(P<0.01),PAl鄄1差异有显著性(P<0.05)。uPA、PAI鄄1和VEGF阳性染色主要定位于血管内皮细胞和瘤细胞胞浆,以肿瘤侵袭边缘和坏死组织周围多见。uPA与VEGF、PAI鄄1与VEGF之间均呈明显正相关(P<0.05)。8例正常脑组织除1例有PAl鄄1微弱表达外,其余均为阴性。结论随脑胶质瘤恶性度增高,uPA、PAl鄄1和VEGF表达增强,三者协同作用,可作为胶质瘤恶性度高和侵袭能力强潜在的分子生物学指标。     

脑源性神经营养因子对细胞外蛋白水解酶激活作用的研究

 目的：研究脑源性神经营养因子 (BDNF) 对细胞外蛋白水解酶表达和激活作用的影响。 方法：体外分离并培养人脐静脉内皮细胞（HUVEC），RT-PCR法检测HUVEC基质金属蛋白酶MMP-2 、MMP-9 和基质金属蛋白酶组织抑制剂TIMP-1、TIMP-2 mRNA的表达，明胶酶谱检测MMP-2和MMP-9蛋白酶活性，纤维蛋白酶谱检测尿激酶型纤溶酶原激活剂（uPA）蛋白酶活性，Western blotting检测uPA、纤溶酶原激活剂抑制剂（PAI）、TIMP-1及TIMP-2表达。 结果：在对HUVEC增殖无明显促进作用的浓度范围内，BDNF可促进无血清培养的HUVEC MMP-2和MMP-9 mRNA表达,并可促进MMP-2和MMP-9酶原的激活产生活性明胶酶，BDNF对TIMP-1和TIMP-2的表达无明显影响。BDNF以浓度和时间依赖性方式上调HUVEC uPA和PAI-1的表达，并可促进uPA的活性。 结论：BDNF可激活MMPs和uPA/PAI相关的蛋白级联。     

基质金属蛋白酶-9和血管内皮生长因子在子痫前期患者胎盘组织中的表达

目的 检测子痫前期患者胎盘组织中RECK、基质金属蛋白酶-9（MMP-9）、血管内皮生长因子（VEGF）的基因表达,探讨它们与胎盘滋养细胞浸润过程的调控关系。 方法 采用RT-PCR、Western blotting、免疫组织化学检测120例妊娠足月剖宫产（正常妊娠、轻度子痫前期、中度子痫前期、重度子痫前期各30例）胎盘组织中RECK、MMP-9、VEGF的基因表达。结果 3组子痫前期患者胎盘组织中MMP-9及VEGF的mRNA表达水平均显著低于正常妊娠组（P<0.05）;重度子痫前期组中RECK mRNA的表达显著高于正常妊娠组（P<0.05）;3组子痫前期患者胎盘组织中MMP-9及VEGF蛋白表达均显著低于正常妊娠组（P<0.05）,中度和重度子痫前期组中RECK蛋白表达显著高于正常妊娠组（P<0.05）。结论 子痫前期患者胎盘中RECK与MMP-9、VEGF之间存在负相关性,它们可能参与了胎盘滋养细胞浅浸润过程的调控。     

Roles of growth factors during peri-implantation development

Several growth factor ligand and receptor gene products havebeen shown to play roles during preimplantation mammalian development.Genes for insulin-like growth factors (IGFs), transforming growthfactors (TGFs), fibroblast growth factor (FGF), platelet-derivedgrowth factor (PDGF) and receptors for insulin, IGF, PDGF, TGFaand epidermal growth factor (EGF) are expressed by early embryosof several species including mouse, rat, cow and sheep. Rolesof growth factors during early development have been demonstratedby addition of purified growth factors to culture medium orby molecular genetic techniques that interfere with gene expression.In this way, it has been shown that successful development ofthe blastocyst is dependent on the action of epidermal growthfactor (EGF) and leukaemia inhibitory factor (LIF). Recent experimentsshow that both LIF and EGF stimulate secretion of urokinase-typeplasminogen activator (uPA) and gelatinase B/ matrix metalloproteinase-9(MMP-9) in day 7 mouse blastocyst outgrowths. At the same time,tissue inhibitors of MMPs (TIMPs) are also expressed by embryonic,decidual and uterine tissues during the implantation process.It appears that LIF may act directly or indirectly, by inducingthe expression of other cytokines, to regulate the temporaland spatial production and activity of proteases and proteaseinhibitors to create a favourable environment for implantation. blastocyst/matrix metalloproteinase/plasminogen activator/tissue inhibitors of metalloproteinases (TIMP)     

The effect of epidermal growth factor on vascular endothelial growth factor secretion by endometrial stromal cells

Endometrial stromal cells undergo morphological and functional changes to facilitate oocyte implantation under regulation of various hormones and growth factors. We studied physiological induction by epidermal growth factor (EGF) of vascular endothelial growth factor (VEGF) in these cells. In human endometrial stromal cells, the effect of EGF, genistein, tryphostin AG1478 (a tyrosine kinase inhibitor), and wortmannin (a phosphatidylinositol 3-kinase inhibitor) on production of VEGF was examined: Total RNA was extracted and VEGF mRNA expression was quantified by Northern analysis. EGF induced production of VEGF by stromal cells in a time-dependent manner; the effect became significant after 12 h and increased further between 24 and 48 h (P<0.05). Dose dependency was also significant (P<0.01). Genistein, tryphostin AG1478, and wortmannin partially suppressed the increase in production induced by EGF (P<0.01, P< 0.01, P<0.01), respectively. Production of EGF by fertilized oocytes and trophoblasts has been reported in early pregnancy. VEGF is believed to be induced by EGF through mechanisms involving tyrosine kinase and phosphatidylinositol 3-kinase. The increase in VEGF may contribute to neovascularization that promotes proliferation of endometrium and placentation. Received: 6 September 2001 / Accepted: 21 May 2002     

PAI-1反义RNA对人主动脉平滑肌细胞中血管内皮生长因子的影响

目的 探讨纤溶酶原激活物抑制剂－1（plasminogen activator inhibitor-1,PAI-1)反义RNA对离体培养的主动脉平滑肌细胞（smooth muscle cell,smc)PAI-1表达的作用及对血管内皮生长因子（vscular endothelial growth factor,VEGF)表达的影响。方法 PCR扩增PAI－1第2外显子,将PCR产物纯化克隆后连入真核细胞表达载体pcDNA3．1,构建PAI－1反应RNA重组质粒。将pcDNA3.1-反应PAI－1重组质粒转染SMC中。通过免疫组化、Western印迹、ELISA检测细胞中PAI－1表达的改变;通过免疫荧光技术观察细胞中PAI－1表达量的变化对VEGF的影响。 结果 转染后第3天、细胞中PAI－1含量最低,VEGF的表达也减少。第5天、PAI－1含量逐渐高,VEGF也相应增加。第7天、PAI－1含量接近于正常,VEGF也增至正常水平。结论 反义PAI－1RNA能有效阻断SMC中PAI－1的蛋白合成,同时抑制细胞中VEGF的表达。     

Regulation of extracellular matrix remodeling following transforming growth factor-beta1/epidermal growth factor-stimulated epithelial-mesenchymal transition in human premalignant keratinocytes

During tumor progression, malignant cells exploit critical developmental and tissue remodeling programs, often promoting a plastic phenotype referred to as an epithelial-mesenchymal transition (EMT). Autocrine/paracrine signaling due to tumor microenvironment cytokines, such as members of the transforming growth factor-beta (TGF-beta) and epidermal growth factor (EGF) families, largely regulates the morphological and invasive phases of the EMT phenotype. Notably, epithelial cell initiation often coincides with a switch in the response of these cells to TGF-beta and is concomitant with EGF receptor amplification. Modeling these events, we have observed that premalignant human keratinocytes, HaCaTs, acquire a highly motile and scattered phenotype indicative of EMT following stimulation with TGF-beta1 and EGF. TGF-beta1 and EGF have been shown to upregulate a number of matrix metalloproteinases (MMP) in epithelial cells, which may in turn play a role in developing metastatic potential in these cells. We have established that an increase in MMP-10 expression occurs following treatment of HaCaT cells with a combination of TGF-beta1 and EGF. This increase in MMP-10 expression paralleled the development of a collagenolytic phenotype that was sensitive to components of the plasminogen activation system, including the plasminogen activator inhibitor type-1 (PAI-1). Significantly high levels of MMP-10 have been detected in squamous cell carcinomas of the head and neck, esophagus, oral cavity and skin. Importantly, TGF-beta1 in addition to upregulating MMP-10 has been shown to upregulate PAI-1 expression in HaCaT cells. Taken together, these observations suggest that TGF-beta1 and EGF play a complex role in modulating proteolytic and transitional events such as EMT that may facilitate the progression of human premalignant epithelial cells toward a more invasive phenotype.     

Hepatocyte growth factor increases expression of vascular endothelial growth factor and plasminogen activator inhibitor-1 in human keratinocytes and the vascular endothelial growth factor receptor flk-1 in human endothelial cells

The pleiotropic growth factor hepatocyte growth factor/scatter factor (HGF/SF) has been implicated by clinical and experimental studies in repair mechanisms in different organs and tissues. However, no data on the impact of HGF/SF in wound healing in the skin are yet available. Proliferating and migrating keratinocytes play a major role in repair processes in the skin by closing the wound. Recent evidence gathered from studies that used gene-deficient mice has implicated the plasminogen activator (PA)/plasmin system in wound healing, which depends on controlled matrix degradation and deposition during cell migration and proliferation. Furthermore, keratinocytes are an important source of vascular endothelial growth factor (VEGF), which is a potent inducer of angiogenesis. In this study, we show that in human keratinocytes HGF/SF but not the related cytokine macrophage stimulating protein (MSP) significantly increases expression of VEGF and plasminogen activator inhibitor-1 (PAI-1) on the level of protein and mRNA. Furthermore, we demonstrate that HGF/SF increases the expression of the VEGF receptor flk-1 in human endothelial cells and that, in an angiogenesis co-culture assay of endothelial cells and keratinocytes, HGF/SF increases endothelial cell tube formation significantly. Therefore, we propose a role for HGF/SF in wound repair in the skin: HGF/SF--produced by activated fibroblasts--increases in keratinocytes the expression of PAI-1, which leads to increased matrix stability during the repair process and which could also limit activation of HGF/SF by proteases such as urokinase-type PA (u-PA) or tissue-type PA (t-PA). Furthermore HGF/SF also increases the expression of VEGF in these cells, thereby initiating angiogenesis in a paracrine manner. This effect would be enhanced by an increased responsiveness of endothelial cells toward VEGF, resulting from the HGF/SF-induced up-regulation of flk-1 on these cells.     

血管内皮生长因子和基质金属蛋白酶-9的表达与胰腺癌侵袭转移的关系

目的 :研究血管内皮生长因子 (VEGF)与基质金属蛋白酶 - 9(MMP - 9)在胰腺癌中的表达与胰腺癌侵袭转移的关系。方法 :采用免疫组化ABC法对 30例胰腺癌手术切除标本的VEGF及MMP- 9蛋白表达进行检测。结果 :VEGF和MMP - 9在胰腺癌组织中的阳性表达率分别为 83 3 % (2 5/ 30 )和60 % (1 8/ 30 ) ,在正常胰腺组织中分别为 45 % (9/ 2 0 )和 2 5 % (5/ 2 0 ) ,癌组织与正常组织间存在显著差异 (P <0 0 5) ;VEGF和MM - 9的阳性表达率与胰腺癌的侵袭转移显著相关。结论 :VEGF和MMP - 9在胰腺癌生长、侵袭和转移过程中起着重要的作用 ,对预测胰腺癌复发、转移具有一定的意义     

Endocrinology and paracrinology: Roles of growth factors during peri-implantation development

Several growth factor ligand and receptor gene products havebeen shown to play roles during preimplantation mammalian development.Genes for insulin-like growth factors (IGFs), transforming growthfactors (TGFs), fibroblast growth factor (FGF), platelet-derivedgrowth factor (PDGF) and receptors for insulin, IGF, PDGF, TGFand epidermal growth factor (EGF) are expressed by early embryosof several species including mouse, rat, cow and sheep. Rolesof growth factors during early development have been demonstratedby addition of purified growth factors to culture medium orby molecular genetic techniques that interfere with gene expression.In this way, it has been shown that successful development ofthe blastocyst is dependent on the action of epidermal growthfactor (EGF) and leukaemia inhibitory factor (LIF). Recent experimentsshow that both LIF and EGF stimulate secretion of urokinase-typeplasminogen activator (uPA) and gelatinase B/ matrix metalloproteinase-9(MMP-9) in day 7 mouse blastocyst outgrowths. At the same time,tissue inhibitors of MMPs (TIMPs) are also expressed by embryonic,decidual and uterine tissues during the implantation process.It appears that LIF may act directly or indirectly, by inducingthe expression of other cytokines, to regulate the temporaland spatial production and activity of proteases and proteaseinhibitors to create a favourable environment for implantation.     

Protein expression of MMP-13, uPA, and PAI-1 in pseudocapsular and interface tissue around implants of loose artificial hip joints and in osteoarthritis

Matrix metalloproteinase 13 (MMP-13), urokinase type plasminogen activator (uPA), and plasminogen activator inhibitor type-1 (PAI-1) have been reported to be involved in aseptic loosening of artificial hip joints. This study for the first time presents the protein levels of all of these factors in synovial-like interfaces between bone and prosthesis and in pseudocapsular tissues surrounding the artificial joint in patients with aseptic loosening (n=17) measured by ELISA. No differences were observed in the antigen expression of MMP-13, uPA, and PAI-1, comparing interface and pseudocapsular tissue. Also, no significant correlation between the protein expression of these factors and years from arthroplasty to revision or to type of fixation (cemented vs. cementless) was observed. As control, MMP-13, uPA, and PAI-1 antigen levels were also determined in the synovium of patients with osteoarthritis (n=10). Yet, the antigen levels of MMP-13, uPA, and PAI-1 in tissue specimens from patients with aseptic loosening of artificial hip joints were significantly higher compared to their expression in synovial capsular tissues obtained from patients with osteoarthritis. In conclusion, this study shows that elevated protein levels of uPA, PAI-1, and MMP-13 in periprosthetic pseudocapsular and interface tissues from patients after total hip replacement due to aseptic loosening seem not to be associated with the patient outcome.     

Regulation of trophoblast invasion by IL-1beta and TGF-beta1

PROBLEM: To investigate the effect of IL-1beta and TGF-beta1 on trophoblast derived proteases and their inhibitors at the mRNA and protein level for elucidation of the mechanism of trophoblast invasion. METHOD OF STUDY: Trophoblast derived proteases and their inhibitors were localized in human placental villi by immunohistochemistry, their regulation at mRNA and protein levels were studied using RT-PCR and zymography, respectively, on trophoblast cells in culture. RESULTS: Trophoblast proteases, matrix metalloproteases (MMP-2, MMP-9), membrane type matrix metalloproteases (MT-MMP1 & 2) and urokinase type plasminogen activator (uPA) were found to be up regulated by IL-1beta while the protease inhibitors, tissue inhibitor of metalloproteases (TIMP-1 & 2) and plasminogen activator inhibitors (PAI-1 & 2) to be up regulated by TGF-beta1. CONCLUSION: Temporo-spatial regulation of trophoblast invasion is the outcome of a balanced interplay between the proteases and their cognate inhibitors. IL-1beta and TGF-beta1 seem to be critical for regulating the protease network thereby effectively controlling the extent to which the trophoblast may invade the maternal endometrium.     

Angiogenesis, vascular endothelial growth factor and the endometrium

Angiogenesis is an essential component of endometrial renewal. The formation of new vessels depends on interactions between various hormones and growth factors, and this review focuses on the expression of angiogenic growth factors in the human endometrium. Peptide and non-peptide angiogenic factors interact during endometrial renewal, including epidermal growth factor (EGF), transforming growth factors (e.g. TGF-beta), platelet-derived endothelial growth factor/thymidine phosphorylase (PD-ECGF/TP), tumour necrosis growth factors and vascular endothelial growth factor (VEGF). Their role in the proliferation and migration of endothelial cells from pre-existing vessels is described, concentrating on VGEF and its receptors (VEG-R1 and -R2), and the fibroblast growth factor (FGF) family. The actions of the products of the VEGF gene are outlined, and the hormonal and non-hormonal control of their localization in the human endometrium and biological actions on vasculature and coagulation are described. Finally, the role of VEGF in menorrhagia is assessed.     

In situ localization of mRNA for the fibrinolytic factors uPA, PAI-1 and uPAR in endometriotic and endometrial tissue

Endometriotic tissue grows invasively. The plasminogen-activating system is suggested to participate in degradation of extracellular matrix (ECM) and modulation of cell adhesion and migration. We have previously demonstrated elevated levels of the fibrinolytic factors urokinase plasminogen activator (uPA) and plasminogen activator inhibitor (PAI-1) in endometriotic tissue and endometrium from women with endometriosis. The aim of the present study was to localize the uPA, PAI-1 and urokinase plasminogen activator receptor (uPAR) mRNA in endometriotic tissue and in endometrium both from women with and without endometriosis. With in situ hybridization, we found that uPA mRNA seems to be up-regulated in endometriotic glands and endometrial stroma as well as PAI-1 mRNA in endometriotic and endometrial stroma from women with endometriosis. uPAR mRNA likewise appears to be up-regulated in both glands and stroma in endometriotic tissue and in endometrial glands from patients compared to endometrial glands and stroma from healthy women. These differences might be important for menstrual shedding and adherence of endometrial fragments to peritoneal lining in women developing endometriosis and for the invasive growth of endometriotic tissue.     

Dysregulation of matrix metalloproteinases and their tissue inhibitors is related to abnormality of left ventricular geometry and function in streptozotocin-induced diabetic minipigs

This study aimed to characterize matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in relation to changes in left ventricle (LV) geometry and function in a porcine model with streptozotocin (STZ)-induced diabetes. In 15 Chinese Guizhou minipigs with STZ-induced diabetes (diabetic group) and 15 age-matched normal controls (control group), Doppler tissue imaging was performed at 6 months of diabetes. Serum MMP-2, -9, TIMP-1, -4 and B-type natriuretic peptide (BNP) were determined. Expression of MMPs, TIMPs, urokinase type-plasminogen activator (uPA), its receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) in aortic intima and LV myocardium was evaluated, with gelatinolytic activities of tissue MMP-2, -9 accessed by zymography. Left ventricle end-diastolic septum thickness (P < 0.05) and mass (P < 0.05) were increased, whereas peak systolic mitral annulus velocity (Sm, P < 0.001), LV systolic (P = 0.01) and diastolic strain (P < 0.001) were significantly decreased in diabetic group than in controls. Diabetic group showed higher expression of TIMP-1, -4 in aortic intima and LV myocardium (P < 0.01 or P < 0.05), with increased collagen content and elevated serum BNP level (P = 0.004) and lower gelatinolytic activities of tissue MMP-2, -9 (all P < 0.05). Semi-quantitative RT-PCR of those diabetic tissues revealed elevated mRNA levels of major TIMPs, uPA, uPAR and PAI-1. Reduction of serum MMP-2 and -9 levels was observed in diabetic group vs. control group (both P < 0.05). This study features elevated levels of TIMP-1, -4, uPA, uPAR and PAI-1, and decreased activities of MMP-2, -9 in aorta and myocardium in STZ-induced diabetic minipigs, indicating that MMP-TIMP dysregulation is associated with LV hypertrophy, cardiac dysfunction and increased cardiovascular fibrosis in diabetes.