SKIP is required for TGF-β1-induced epithelial mesenchymal transition and migration in transformed keratinocytes

Transforming growth factor-β1 (TGF-β1) potently induces the epithelial-mesenchymal transition (EMT) during tumoral progression. Although Sky-interacting protein (SKIP) regulates TGF-β1-induced Smad activation, its role in the induction of cell malignance remains uncertain. We found that TGF-β1 increases SKIP expression in PDV cells. In cells stably transfected with SKIP antisense, AS-S, Smad3 activation decreased, along with an inhibition of TGF-β1-induced EMT, and the cells were sensitized to the TGF-β1-dependent inhibition of proliferation. Also, AS-S cells showed a weaker migration and invasion response. Moreover, TGF-β1-induced urokinase-type plasminogen activator expression was inhibited, concomitantly with a TGF-β1-independent increment of the plasminogen-activator inhibitor-1 expression. Thus, these results suggest that SKIP is required for EMT and invasiveness induced by TGF-β1 in transformed cells.     

重组抗体—尿激酶导向溶栓剂的基因构建及表达

为了获得高效、高特异性溶栓药物,应用基因工程技术,成功的表达了由人源化抗人活化血小板单抗和单链尿酶组成的抗体导向溶栓剂（ＳＺ５１Ｈｕ－ｓｃｕＰＡ）。通过基因重组ＰＣＲ方法将ｓｃｕＰＡ全长ｃＤＮＡ的Ｎ末端连接在ＳＺ５１重链恒区ＣＨ３末端,构建了含有目的蛋白融合基因的真核表达载体αｌｙｓ３０－ＳＺ５１ＶＨ／Ｈｕ－ｓｃｕＰＡ。采用脂转染法将表达载体导入分泌ＳＺ５１ＶＫ／Ｈｕ轻链的小鼠骨髓瘤细胞中,筛选出     

The art of arteriogenesis

The identification of collateral artery growth (arteriogenesis) as the only mechanism to compensate for the loss of an occluded artery forced us to define the mechanisms responsible for this type of vessel growth. To achieve this, a variety of coronary as well as peripheral models of arteriogenesis have been developed. Based on these studies it is obvious that arteriogenesis obeys different mechanisms than angiogenesis, the sprouting of capillaries. Upon occlusion of an artery, the blood flow is redirected into preexisting arteriolar anastomoses that experience increased mechanical forces such as shear stress and circum ferential wall stress. The endothelium of the arteriolar connections is then activated, resulting in an increased release of monocyte-attracting proteins as well as an upregulation of adhesion molecules. Upon adherence and extravasation, monocytes promote arteriogenesis by supplying growth factors and cytokines that bind to receptors that are expressed on vascular cells within a limited time frame. Animal studies evidenced that factors, such as monocyte chemoattractant protein-1, granulocyte-monocyte colony-stimulating factor, or transforming growth factor-β₁, that either attract or prolong the lifetime of monocytes efficiently enhance collateral artery growth, an effect that was seen only to a minor degree after application of a single growth factor. Bone marrow-derived stems cells and endothelial progenitor cells do not incorporate in growing arteries but, rather, function as supporting cells. Complete elucidation of the mechanisms of arteriogenesis may lead to efficacious therapies counteracting the devastating consequences of vascular occlusive diseases.     

Arsenic trioxide (As2O3) inhibits invasion of HT1080 human fibrosarcoma cells: role of nuclear factor-kappaB and reactive oxygen species

In order to define the role of As2O3 in regulating the tumor cell invasiveness, the effects of As2O3 on secretion of matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA), and in vitro invasion of HT1080 human fibrosarcoma cells were examined. As2O3 inhibited cell adhesion to the collagen matrix in a concentration dependent manner, whereas the same treatment enhanced cell to cell interaction. In addition, As2O3 inhibited migration and invasion of HT1080 cells stimulated with phorbol 12-myristate 13-aceate (PMA), and suppressed the expression of MMP-2, -9, membrane type-1 MMP, uPA, and uPA receptor (uPAR). In contrast, As2O3 increased the expression of tissue inhibitor of metalloproteinase (TIMP)-1 and PA inhibitor (PAI)-1, and reduced the MMP-2, -9, and uPA promoter activity in the presence and absence of PMA. Furthermore, the promoter stimulating and DNA binding activity of nuclear factor-kappaB (NF-kappaB) was blocked by As2O3, whereas the activator protein-1 activity was unchanged. Pretreatment of the cells with N-acetyl-L-cysteine (NAC) significantly prevented suppression of MMPs and uPA secretion, DNA binding activity of NF-kappaB, and in vitro invasion of HT1080 cells by As2O3, suggesting a role of reactive oxygen species (ROS) in this process. These results suggest that As2O3 inhibits tumor cell invasion by modulating the MMPs/TIMPs and uPA/uPAR/PAI systems of extracellular matrix (ECM) degradation. In addition, the generation of ROS and subsequent suppression of NF-kappaB activity by As2O3 might partly be responsible for the phenomena. Overall, As2O3 shows potent activity controlling tumor cell invasiveness in vitro.     

A novel gene delivery system targeting urokinase receptor

Viral vectors are widely used in gene therapy due totheir high efficiency of gene transfer. However, majordisadvantages of viral vectors for gene transfer include thelimitation of cell type specificity and the size of incor-porated DNA, the potential risk…     

Construction, expression, and characterization of a recombinant annexin B1-low molecular weight urokinase chimera in Escherichia coli

Thrombolytic therapy has been a major advance in thtreatment of myocardial infarction over the last twdecades. Urokinase (UK), streptokinase (SK), and tissuplasminogen activator (t-PA) are the common availablthrombolytic agents. These agents, however, hav…     

尿激酶颈动脉灌注治疗急性脑梗死疗效观察

目的：研究小剂量尿激酶颈动脉加压灌注治疗急性脑梗死的效果。方法选择８０例急性梗死住院病人按入院顺序随机分为治疗组（颈动脉灌注组）和对照组,各４０例,治疗组入院后即给予尿激酶３０万单位于患侧颈动脉加压灌注,同时给予低分子右旋糖酐５００ｍｌ、脉胳宁２０ｍｌ、有脑水肿者给予甘露醇、细胞活化剂、钙离子拮抗剂同时应用;对照组除尿激酶外用药相同,两组于治疗前及治疗后１５天按临床神经功能缺损程度评分标准作出疗效     

RGD肽与尿激酶B链融合蛋白原核重组表达质粒的构建,表达和？…

将化学合成的ＲＧＤ肽（Ａｒｇ－Ｇｌｙ－Ａｓｐ）编码寡核苷酸与尿激酶Ｂ链ｃＤＮＡ相连成为融合基因后,克隆至原核表达质粒ｐＢＶ２２０中,在ＰＲＰＬ自动子的作用下,经４２℃热诱导,在大肠杆菌ＤＨ５α中获得了融合基因的表达,其表达量占菌体总蛋白的９．２％,表达产物以无活性的包含体形式存在。经变复性处理得到纯化的融合基因的表达产物,经Ｗｅｓｔｅｒｎ－ｂｌｏｔｔｉｎｇ分析表明产物具有与天然尿激酶相似的抗原性,     

重组人尿激酶原的体外变复性研究

重组人尿激酶原在大肠杆菌中过量表达时形成不溶物包涵体,需经体外变复性后才能获得生物活性。本文旨在提高包涵体中变性尿激酶原的复性效率,通过对pH,温度,变性剂种类及浓度,蛋白浓度,以及巯基氧化还原对的比率等的定性定量分析,研究重组人尿激酶原体外变复性的基本条件,并比较了添加某些非特异有效成分,脉冲稀释,梯度透析等方法对提高重组人尿激酶原体外变复性效率的作用。确定了重组人尿激酶原体外变复性的适宜方法,复性效率可达20%～30%。     

留置中心静脉导管加尿激酶心包内灌洗治疗急性结核性心包炎的 临床疗效观察

目的:观察留置中心静脉导管引流加尿激酶心包内灌洗治疗急性结核性心包炎的疗效。方法:自1996年1月～2009年5月对我院48例临床确诊为急性结核性心包炎伴中到大量积液的患者(病程均短于1月),男28例,女20例,年龄14～72岁。随机分为两组,治疗组(常规抗结核、肾上腺糖皮质激素治疗的基础上给予留置中心静脉导管心包引流加心包内尿激酶灌洗治疗)或对照组(常规抗结核、肾上腺糖皮质激素治疗基础上给予留置中心静脉导管引流)。观察并比较两组穿刺并发症(心包内出血、心律失常及感染),治疗前、后心包膜厚度的变化,拔管时心包积液的残留量,以及通过电话问询及心脏超声随访并发症,随访截止日期为2010年5月。随访期限为11～132个月。结果:治疗组与对照组比较,治疗组治疗1周及2周后心包膜厚度的变化、拔管时积液残留量及发生心包缩窄方面有明显差异(P<0.05),穿刺相关并发症方面无明显差异(P>0.05)。全部治疗组患者给予尿激酶治疗后未见心包内出血及系统性出血并发症。随访期内无一例发生死亡,治疗组及对照组分别有1例(4.2%)及8例(33.3%)发生心包缩窄。结论:留置中心静脉导管加尿激酶灌洗治疗急性结核性心包炎安全、可行,心包积液引流彻底,拔管时间早,心包膜增厚程度显著减轻,心包粘连机会减少,能有效地预防患者心包缩窄的发生。