人Delta-like4ext-26-217蛋白原核表达载体的构建及表达

构建人Delta-like4ext-26-217原核表达载体并表达。采用PCR方法扩增hDll4ext-26-217多核苷酸序列,克隆入pMD18T载体。测序正确后,将其亚克隆入pET32a( )原核表达载体,获得pET32a( )-hDll4ext-26-217载体。以该载体转化E.coli菌株BL21,IPTG诱导其表达。采用SDS-PAGE、Western Blot方法鉴定目的蛋白的表达。结果表明,采用SDS-PAGE,Western Blot等方法均可检测到目的蛋白TRX/hDll4ext -26-217,分子量约42.2 KD,主要以包涵体形式大量存在。以上结果为Detla-like4功能的进一步研究奠定了基础。     

darbufelone对胃癌SGC-7901细胞裸鼠移植瘤血管生成的影响

目的观察环氧合酶-2／5-脂氧合酶双重抑制剂darbufelone对人胃癌皮下移植瘤血管生成的影响,并初步探讨其机制。方法建立裸鼠实体瘤模型,随机分为darbufelone组和对照组,darbufelone及生理盐水分别连续灌服4周。测量肿瘤质量、体积,计算抑瘤率;免疫组化检测CD34并计算微血管密度;RT—PCR法及Western blot法分析移植瘤组织中MMP-9、VEGF的表达。结果darbufelone可明显抑制裸鼠移植瘤的生长,质量抑瘤率为58．42％,体积抑瘤率为67．13％。darbufelone组的微血管密度（MVD）（15．36±0．30）明显低于对照组（29．47±0．63）（P〈0．05）;darbufelone组肿瘤组织中VEGF及MMP-9在基因水平及蛋白水平的表达（P〈0．05）。结论darbufelone能有效抑制裸鼠移植瘤的生长,减少移植瘤组织中VEGF及MMP-9的表达,抑制肿瘤的微血管生成,具有抗血管生成的作用。     

Progress in studies of angiostatin and its anti-tumor effects

Angiostatin is a 38 ku circulating angiogenesis inhibitor purified from the serum and urine of mice bearing a murine Lewis lung carcinoma. It is regarded as an internal fragment of plasminogen containing the first 4 Kringle structures. In vitro, angiostatin specifically inhibits endothelial cell proliferation. In vivo, it inhibits angiogenesis and suppresses the growth of such primary tumors as Lewis lung carcinoma and hemangioendotheliolma in mice.     

Slit-Robo信号通路在心血管发育中的作用

近期研究表明, Slit-Robo信号通路对心血管系统的发育和再生发挥了重要功能. Slit3作为促血管新生因子, 能够与其受体Robo4结合, 通过RhoGTPase信号通路调控多个生理和病理过程中的血管新生. Slit3-Robo4信号通路的激活能够促进工程组织中血管网络的形成. 硫酸乙酰肝素通过Slit3-Robo4通路能够调节膈肌发育及其血管新生. Slit-Robo信号通路还参与调控心脏系统静脉回流和心包膜的发育. Slit3的缺失会导致小鼠发育过程中的肾脏缺失和输尿管发育不全. 因此, 进一步研究Slit3-Robo4信号通路对于阐释心血管系统发育和疾病的病因具有重要理论意义, 有望为心血管疾病的预防和治疗提供有力的药物作用靶点, 促进有效药物的开发.     

黄芪丹参配伍提取物经VEGF、Ang1／Tie2通路对MI大鼠血管新生的病理影响

为观察黄芪、丹参配伍提取物对心肌梗死大鼠VEGF（vascular endothelial growth factor）、血管生成素Ang1及其受体酪氨酸激酶Tie2信号通路的表达影响。通过心肌梗死大鼠模型复制成功后分为假手术对照组、模型组、黄芪、丹参配伍提取物低、中、高剂量组,分别予以对应药物灌胃4周。观察大鼠一般生活状态,并分别采用HE染色和免疫组织化学染色测试大鼠心肌组织病理形态结构和VEGF、Ang1、Tie2的蛋白表达。结果表明：模型组心肌结构紊乱伴有炎性侵润,VEGF、Ang1和Tie2蛋白表达较假手术对照组有所增加（P＜0.05）;低、中、高剂量组随着药物浓度梯度增加,心肌结构逐渐规整,内皮细胞完整、新生血管增多,与模型组比较差异显著（P＜0.05或P＜0.01）。可见黄芪、丹参配伍提取物可以上调心肌梗死大鼠VEGF、Ang1和Tie2的表达,促进血管新生。     

天然产物抗血管生成的研究进展

抗血管生成治疗已成为恶性肿瘤治疗的重要途径。本文对近年来抗肿瘤血管生成的天然产物研究进行了归类,已有研究发现萜类、酚类、黄酮类、生物碱类和蒽醌类等天然产物有抑制血管生成的作用,并且通过细胞与分子学实验揭示了其抑制血管生成的机理。本文综述了近年天然产物抑制肿瘤血管生成的研究成果,希望能为中药材抗肿瘤药物开发提供新思路。     

Heparanase involvement in physiology and disease

Heparanase is an endoglycosidase that degrades heparan sulfate on the cell surface and extracellular matrix. The physiological functions of heparanase include heparan sulfate turnover, embryo development, hair growth, and wound healing. Heparanase is implicated in a variety of pathologies, such as tumor growth, angiogenesis, metastasis, inflammation, and glomerular diseases. Heparanase overexpression in a variety of malignant tumors suggests that it could be a target for anti-cancer therapy.     

Curcumin: From ancient medicine to current clinical trials

Curcumin is the active ingredient in the traditional herbal remedy and dietary spice turmeric (Curcuma longa). Curcumin has a surprisingly wide range of beneficial properties, including anti-inflammatory, antioxidant, chemopreventive and chemotherapeutic activity. The pleiotropic activities of curcumin derive from its complex chemistry as well as its ability to influence multiple signaling pathways, including survival pathways such as those regulated by NF-kappaB, Akt, and growth factors; cytoprotective pathways dependent on Nrf2; and metastatic and angiogenic pathways. Curcumin is a free radical scavenger and hydrogen donor, and exhibits both pro- and antioxidant activity. It also binds metals, particularly iron and copper, and can function as an iron chelator. Curcumin is remarkably non-toxic and exhibits limited bioavailability. Curcumin exhibits great promise as a therapeutic agent, and is currently in human clinical trials for a variety of conditions, including multiple myeloma, pancreatic cancer, myelodysplastic syndromes, colon cancer, psoriasis and Alzheimer's disease.     

Progesterone inhibits human endothelial cell proliferation through a p53-dependent pathway

Previous studies have shown that progesterone inhibits endothelial cell proliferation through a nuclear receptor-mediated mechanism. Here, we further demonstrate that progesterone at physiologic levels (5 – 500 nM) dose- and time-dependently inhibited DNA synthesis of cultured human umbilical vein endothelial cells (HUVEC). The mRNA and protein levels of p21, p27, and p53 in HUVEC were increased by progesterone. The formation of CDK2-p21 and CDK2-p27 were increased and the CDK2 activity was decreased in the progesterone-treated HUVEC. The progesterone-inhibited [3H]thymidine incorporation was completely blocked when the expressions of p21 and p27 were knocked-down together. Transfection of HUVEC with dominant negative p53 cDNA prevented the progesterone-induced increases in p21 and p27 promoter activity and protein level, decreases in thymidine incorporation, and capillary-like tube formation. Matrigel angiogenesis assay in mice demonstrated the antiangiogenic effect of progesterone in vivo. These findings demonstrate for the first time that progesterone inhibited endothelial cell proliferation through a p53-dependent pathway. Received 28 July 2008; received after revision 25 September 2008; accepted 26 September 2008     

丹参酮ⅡA促内皮细胞增殖作用研究

目的:观察活血化瘀类中药丹参的活性成分—丹参酮ⅡA对内皮细胞增殖的影响、及其适宜作用浓度和时间,并初步探讨其作用机制。方法:不同浓度丹参酮ⅡA作用于人脐静脉内皮细胞系(HUV-EC-C)不同时间,利用SRB方法测得其吸光度值(OD),以确定各组内皮细胞增殖情况,并筛选适宜浓度和适宜时间点。结果:丹参酮ⅡA具有显著的促人脐静脉内皮细胞(HUV-EC-C)增殖效应,其中终浓度6 mg/L干预48 h效应最为显著。结论:丹参酮ⅡA能够显著促进内皮细胞增殖,提示其具有促血管生成作用。