丹酚酸B对鸡胚绒毛尿囊膜血管新生作用的影响

目的探讨丹酚酸B对鸡胚绒毛尿囊膜血管新生的影响。方法将7日龄鸡胚制备鸡胚绒毛尿囊膜(chick embryo chorioallantoic membrane,CAM)模型,随机分为6个组,分别为PBS(phosphatebuffer solution)对照组,丹酚酸B 4个剂量组(150、50、16.67、5.56 mg.L-1)及VEGF(vascular endo-thelial growth factor)组,培养3 d后时采集数据进行评价。结果丹酚酸B 150、50 mg.L-1组血管新生面积明显高于PBS(phosphate buffer solution)对照组(P<0.01,P<0.05)。结论丹酚酸B可明显促进鸡胚绒毛尿囊膜血管新生。     

The in vivo evaluation of anti-angiogenic effects of Hypericum essential oils using the chorioallantoic membrane assay

Context. Hypericum species including Hypericum confertum Choisy, H. hircinum L., H. hyssopifolium Chaix. subsp. elongatum (Ledeb.) Woron var. microcalycinum (Boiss. &; Heldr.) Boiss. and H. perforatum L. (Clusiaceae) are used as medicinal plants in Turkey.

Objective: The anti-angiogenic evaluation of Hypericum essential oils using the chick embryo chorioallantoic membrane (CAM) assay are performed with this study for the first time.

Materials and methods: The anti-angiogenic activity of Hypericum essential oils (0.5–5.0?mg/ml) was evaluated in vivo using the CAM assay, compared to standard anti-angiogenic substances at the same concentrations, in trice replicated independent assays. GC and GC-MS analyses were carried out simultaneously to identify the chemical compositions of the Hypericum essential oils.

Results: The CAM treated with H. perforatum essential oil showed anti-angiogenic effect (score 0.6?±?0.3) at 50?µg/pellet concentration, whereas other tested Hypericum essential oils showed no effect compared to the standards (e.g. suramin score 0.5?±?0.2). Furthermore, the tested oils showed neither membrane toxicity nor irritation at the tested concentrations. The major compound of the essential oil of H. confertum was identified as germacrene D (30.2%). The major compound of the essential oils of the H. hircinum. H. hyssopifolium subsp. elongatum var. microcalycinum and H. perforatum was identified as α-pinene (88.3, 57.8, 33.3%), respectively.

Discussion and conclusion. Hypericum species and in particular H. perforatum essential oil may have important effect toward wound healing and various inflammations. The data obtained in this experiment suggest further investigations on various cancers due to its anti-angiogenic effects observed.     

The effects of cadmium on VEGF-mediated angiogenesis in HUVECs

Cadmium (Cd) is a highly toxic element that causes morphologic alterations and dysfunction in blood vessels. The altered vascular function caused by cadmium has been implicated in a range of chronic diseases, including hypertension. The effects of cadmium are a multisystem phenomenon involving inflammation, hypertrophy, apoptosis, angiogenesis and important processes involved in vascular remodeling systems. Vascular endothelial growth factor (VEGF) plays a major role in cell growth and angiogenesis under pathologic conditions. VEGF secretion is related to anti-apoptosis protein expression and attenuates apoptosis in endothelial cells. This study examined the VEGF-dependent mechanisms of angiogenesis and apoptosis in cadmium-treated endothelial cells (HUVECs). The effects and mechanisms of cadmium in endothelial cells (HUVECs) were examined by exposing the cells to different doses of cadmium chloride (2.5-40 μ m). After the cadmium treatment, the angiogenesis and apoptosis mechanisms related to VEGF in cadmium-treated HUVECs were examined. As a result, the low concentration of cadmium increased the tube formation in HUVECs. In addition, cadmium at concentrations of 5 and 10 μ m increased VEGF secretion and VEGFR2 activity, which suggest that cadmium affects the growth of blood vessels. All three MAPK pathways, namely ERK, JNK and p38, were activated by cadmium in HUVECs. However, high concentrations of cadmium caused cell damage, disrupted tube formation and inhibited VEGF expression and the activities of VEGFR2 and MAPK in HUVECs. Cadmium has dual functions through VEGF-dependent mechanisms in a dose-dependent manner. In this study, the dual effects of cadmium might alter angiogenesis and induce apoptosis through VEGF pathways in HUVECs.     

Angiopoietin/Tie receptor system: emerging targets for therapeutic angiogenesis and anti-angiogenic therapy

Balanced regulation of endothelial cell function and co-ordination of endothelial cells and periendothelial support cells by angiogenic growth factors and cell type-specific receptor tyrosine kinases is crucially involved in physiological angiogenesis. Disturbance of this fine-tuned balance is associated with disease-related neoangiogenesis, such as in tumour angiogenesis or in retinopathy, or in insufficient angiogenesis in occlusive vascular disease. In addition to the well known function of vascular endothelial growth factor (VEGF) as an endothelial cell-specific angiogenesis inducer and survival factor, recent studies on angiopoietins and their receptors have provided insight into the interplay of these endothelium-specific ligand-receptor systems in formation, maintenance and remodelling of the vasculature. Knowledge of the mechanisms by which these ligand-receptor systems are involved in regulation of the interaction of endothelial cells and their periendothelial support cells opens new opportunities for therapeutic angiogenesis to induce formation of functional blood vessels in occlusive disease, as well as to complement and/or enhance current anti-VEGF-based strategies for anti-angiogenic therapy.     

LYG-202, a Newly Synthesized Flavonoid,Exhibits Potent Anti-angiogenic Activity In Vitro and In Vivo

LYG-202 (C₂₅H₃₀N₂O₅) is a newly synthesized flavonoid that has been confirmed to possess an antitumor effect, but the mechanism is unclear. Our present study was performed to identify the anti-angiogenic activity of this novel compound in vitro and in vivo. LYG-202 inhibited vascular endothelial growth factor (VEGF) stimulated migration and tube formation of human umbilical vein endothelial cells and arrested microvessel outgrowth from rat aortic rings in vitro. Meanwhile, LYG-202 suppressed the neovascularization of Chicken Chorioallantoic Membrane in vivo. Mechanistic studies revealed that LYG-202 suppressed the VEGF-induced tyrosine phosphorylation of KDR/Flk-1 (VEGFR-2) as well as its downstream protein kinases activation, by decreasing phosphorylated forms of serine/threonine kinase Akt, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase. LYG-202 exerts anti-angiogenic activity both in vitro and in vivo, and these results suggest that it deserves further investigation as a promising anti–tumor angiogenesis compound.     

巴戟天醇提取物促大鼠缺血心肌治疗性血管生成的实验研究

目的探讨巴戟天糖链(MOO)对急性心肌梗死(AMI)大鼠缺血心肌治疗性血管生成的影响及其机制。方法♂Wistar大鼠,结扎冠状动脉左前降支,成功制成AMI模型40只,随机分为MOO小、中、大剂量组、麝香保心丸组及模型组,每组8只。另取10只建立假手术组。药物治疗组分别灌胃给予巴戟天醇提物水溶性部分(0.7、1.4、2.8mg.kg-1.d-1)及麝香保心丸悬浊液(30mg.kg-1.d-1),其余两组灌胃给予等量蒸馏水。连续灌胃6wk后处死大鼠,心肌取材,应用免疫组织化学法检测大鼠缺血心肌Ⅷ因子及血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)、碱性成纤维细胞生长因子(basic fibroblast growthfactor,bFGF)蛋白表达情况;计算微血管密度(microvessecdensity,MVD),用图像分析软件测定VEGF及bFGF表达灰度值,并进行半定量分析。结果与模型组相比,MOO中、大剂量组能增加缺血心肌MVD及VEGF、bFGF灰度值(P<0.05),但作用弱于麝香保心丸组(P<0.05);MOO3个剂量组之间MVD差异均有显著性(P<0.05);MOO3个剂量组之间VEGF灰度值差异均有显著性(P<0.05);MOO中、大剂量组bFGF灰度值与小剂量组相比差异有显著性(P<0.05)。结论MOO可促进AMI后大鼠缺血心肌的血管生成,其机制可能与上调缺血心肌VEGF、bFGF蛋白的表达有关。     

New 2-amino-(5-cyanothiazol-2-yl) pyridines: KDR inhibitors with improved pharmacokinetic profile

In both animal and human settings, inhibition of the vascular endothelial growth factor (VEGF) pathway has proven to be a valuable approach to reduce tumour growth by limiting the formation of new capillaries from existing vasculature (angiogenesis). Endothelial cell proliferation and migration, two critical steps in angiogenesis, are mediated through a specific VEGF receptor, the kinase insert domain-containing receptor (KDR), expressed at the cell surface. Over the past few years, the search for small molecule inhibitors of the kinase activity of this receptor has been a very active area leading to the discovery of a variety of chemical leads, several of which are undergoing evaluation in clinical trials. Merck has been very involved in this field, delivering chemically diverse KDR inhibitors. In this patent application, a team from Merck discloses 2-amino-(5-cyanothiazol-2-yl)pyridines. Members of this class of inhibitors possess improved pharmacokinetics.     

Effect of a dihydrobenzofuran derivative on lipid hydroperoxide-induced rabbit corneal neovascularization

The aim of this study was to investigate the effect of A-3922, a dihydrobenzofuran derivative, on linoleic acid hydroperoxide (LHP)-induced corneal neovascularization (NV) in a rabbit model. Male New Zealand rabbits received intraperitoneal (i.p.) injections of 10 or 30 mg/kg per day A-3922 or its vehicle as control for 3 days. One day after i.p. injections, LHP was injected with a 30-gauge needle into the corneal stroma of the superior quadrant 4.5-mm below the limbus. Photographs of the vessels were taken for digital analysis with a surgical microscope. Vascular endothelial growth factor (VEGF) was measured using an immunoassay kit, and matrix metalloproteinase (MMP)-9 was measured by gelatin zymography in corneal samples. At 7 days post-LHP injection, the total vessel length was 26.7 +/- 3.8 mm in the control animals (n = 8), 16.1 +/- 0.8 mm in the A-3922 (10 mg/kg)-treated group (n = 5), and 11.4 +/- 2.1 mm in the 30 mg/kg group (n = 8, P<0.01 vs control), respectively. After LHP injection, the content of VEGF and MMP-9 activity were increased in the superior cornea, but these were not influenced by A-3922 treatments. These results indicate that LHP-induced corneal NV is inhibited by treatment with A-3922 and therefore may represent a potential pharmacological intervention for ocular neovascularization disorders.     

VEGF receptor kinase inhibitors: phthalazines,anthranilamides and related structures

Inhibition of vascular endothelial growth factor receptor (VEGFR) signalling, using either antibodies or small molecule inhibitors of the VEGFR kinase domain, has become a major area of research in oncology. The phthalazine PTK787/ZK222584, first published in the literature in 1998, is one of the most advanced VEGFR inhibitors in the clinic. This paper provides an update on the patenting activity related to the phthalazine class. In addition, newer kinase inhibitor pharmacophores derived from this class (e.g., anthranilamides) will be reviewed.     

Polymorphisms of VEGFA gene and susceptibility to hemorrhage risk of brain arteriovenous malformations in a Chinese population

Aim:

To evaluate the influence of the vascular endothelial growth factor A (VEGFA) polymorphisms on risk of presentation with intracerebral hemorrhage (ICH).

Methods:

Nine selected VEGFA single-nucleotide polymorphisms (SNPs) were genotyped in 311 patients with brain arteriovenous malformations (BAVM) in a Chinese population. Associations between individual SNPs/haplotypes and the hemorrhage risk of BAVMs were evaluated using logistic regression analysis.

Results:

In the single-locus analysis, rs1547651 was associated with increased risk of ICH (adjusted OR=2.11, 95% CI=1.01–4.42 compared with the AA genotype). In particular, an increased risk for ICH was associated with this variant in female patients (adjusted OR=3.21, and 95% CI=0.99–10.36). Haplotype-based analyses revealed that haplotype ''GC'' in block 1 and haplotype ''ACC'' in block 2 were associated with a 30%–38% reduction in the risk of ICH in patients with BAVMs compared to the most common haplotype (P_sim=0.033 and P_sim=0.005, respectively). The protective effect of haplotype ''ACC'' in block 2 was more evident in male patients and subjects with BAVMs of a size ≥3 cm (adjusted OR=0.57, 95% CI=0.34–0.97 and adjusted OR=0.57, 95% CI=0.31–0.86, respectively).

Conclusion:

The results suggest that VEGFA gene variants may contribute to ICH risk of BAVM.     

Inhibitors targeting hepatocyte growth factor receptor and vascular endothelial growth factor receptor tyrosine kinases

Amgen disclosed a series of 4-heteroaryloxy quinoline/quinazoline compounds as multiple kinase inhibitors, including hepatocyte growth factor (HGF) receptor tyrosine kinase c-Met and vascular endothelial growth factor (VEGF) receptor tyrosine kinase. These compounds are stated to have wide therapeutic applications for the treatment of a variety of cancers, hypertension, arteriosclerosis, myocardial infarction and rheumatoid arthritis.     

Clitocybin A, a novel isoindolinone, from the mushroom Clitocybe aurantiaca, inhibits cell proliferation through G1 phase arrest by regulating the PI3K/Akt cascade in vascular smooth muscle cells

Abnormal proliferation of vascular smooth muscle cells (VSMCs) plays an essential role in the pathogenesis of vascular diseases, such as atherosclerosis, hypertension, and restenosis. Clitocybin A, a novel isoindolinone, isolated from the culture broth of mushroom Clitocybe aurantiaca has been reported to possess free radical scavenging activity. However, the antiproliferative effects of clitocybin A on VSMCs are unknown. In the present study, we investigated the effect of clitocybin A on platelet-derived growth factor (PDGF)-BB-induced proliferation of VSMCs and examined the molecular basis of the underlying mechanism. Clitocybin A inhibited DNA synthesis and cell proliferation. In accordance with these findings, clitocybin A blocked the PDGF-BB-inducible progression through G0/G1 to S phase of the cell cycle in synchronized cells and decreased the expression of cyclin-dependent kinase (CDK) 2, CDK4, cyclin D1, cyclin E, and proliferative cell nuclear antigen. In addition, clitocybin A inhibited the PDGF-BB-induced phosphorylation of phosphatidylinositol 3 kinase (PI3K) / Akt kinase. However, clitocybin A did not change the expression levels of extracellular signal-related kinase (ERK) 1/2, phospholipase C-γ1, and PDGF-Rβ phosphorylation. These results indicate that clitocybin A may inhibit VSMCs proliferation through G1 phase arrest by regulating the PI3K/Akt pathway.     

Vascular endothelial growth factor (VEGF) antibody significantly increases the risk of hand–foot skin reaction to multikinase inhibitors (MKIs): A systematic literature review and meta‐analysis

With the use of multikinase inhibitors (MKIs) having emerged in recent years, skin toxicities such as hand–foot skin reaction (HFSR) are primary side effects, and they lack effective prediction methods. Here, we updated a previous systematic review by establishing a meta‐analysis of the risk of developing HFSR among patients receiving MKIs and antivascular endothelial growth factor antibody. Publications from PubMed and abstracts presented at the American Society of Clinical Oncology Annual Meeting up to February 5, 2015, were searched to identify relevant studies, and a total of 236 patients with metastatic tumours in nine trials were included for analysis. In the meta‐analysis, the pooled incidence rates of all‐grade and high‐grade HFSR among patients who received the combination therapy were 56.9% [95% confidence interval (CI), 45%‐71.1%] and 14.3% (95% CI, 9%‐24.2%), respectively, with significant differences observed with MKI monotherapy (P < .05). Further subgroup analysis demonstrated that increasing the dosages of bevacizumab (77.8% vs 51.1%, P = .04) and MKIs (64.3% vs 52.6%, P = .02) significantly increased HFSR incidence. Moreover, combination with chemotherapy exerted a minimal effect on HFSR risk (61% vs 55.3%, P = .5). This updated review and meta‐analysis confirm the increased risk of HFSR incidence due to the use of MKIs and antivascular endothelial growth factor antibody. Thus, using these therapies requires safety standards.     

Bioinspired tissue engineering: the great promise of protein delivery technologies

The concept of developing a tissue either in vitro or in vivo taking inspiration from physiological events has prompted toward the integration of molecular signals such as growth factors (GFs) in tissue engineering strategies with the aim to guide cell proliferation, differentiation and migration. After the first studies, the awareness emerged that a fine tuning of GF levels in the scaffold, when present, and at boundary with healthy tissue was needed to give successful results. Thus, the modality of GF presentation to cells has been recognized as a key fundamental in many tissue engineering applications and applied through different approaches. In this scenario the potential of particulate systems for GF delivery was promptly perceived as a mean to protect GFs during tissue regrowth and to offer adequate control over release rate. The use of tissue engineering constructs based on GF-loaded particles integrated in different scaffold types has impressively grown in recent years and led to significant advances in the field. Release of more than one GF at rates mimicking in vivo situation has become possible as well as to exert a fine control over GF spatial concentration by developing constructs with specific areas of bioactivities. However, if we consider the strategies for protein delivery currently applied in tissue engineering, it is soon realized that much more can be done. Thus, the aim here is to review some tissue engineering approaches involving the use of GFs by the point of view of delivery issues trying to highlight the remarkable impact that particulate systems can have in the next future.     

OSU-A9 inhibits angiogenesis in human umbilical vein endothelial cells via disrupting Akt–NF-κB and MAPK signaling pathways

Since the introduction of angiogenesis as a useful target for cancer therapy, few agents have been approved for clinical use due to the rapid development of resistance. This problem can be minimized by simultaneous targeting of multiple angiogenesis signaling pathways, a potential strategy in cancer management known as polypharmacology. The current study aimed at exploring the anti-angiogenic activity of OSU-A9, an indole-3-carbinol-derived pleotropic agent that targets mainly Akt–nuclear factor-kappa B (NF-κB) signaling which regulates many key players of angiogenesis such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Human umbilical vein endothelial cells (HUVECs) were used to study the in vitro anti-angiogenic effect of OSU-A9 on several key steps of angiogenesis. Results showed that OSU-A9 effectively inhibited cell proliferation and induced apoptosis and cell cycle arrest in HUVECs. Besides, OSU-A9 inhibited angiogenesis as evidenced by abrogation of migration/invasion and Matrigel tube formation in HUVECs and attenuation of the in vivo neovascularization in the chicken chorioallantoic membrane assay. Mechanistically, Western blot, RT-PCR and ELISA analyses showed the ability of OSU-A9 to inhibit MMP-2 production and VEGF expression induced by hypoxia or phorbol-12-myristyl-13-acetate. Furthermore, dual inhibition of Akt–NF-κB and mitogen-activated protein kinase (MAPK) signaling, the key regulators of angiogenesis, was observed. Together, the current study highlights evidences for the promising anti-angiogenic activity of OSU-A9, at least in part through the inhibition of Akt–NF-κB and MAPK signaling and their consequent inhibition of VEGF and MMP-2. These findings support OSU-A9's clinical promise as a component of anticancer therapy.