New Ops:Vasc Leakage Inhibition Protects Against Anthrax Pleural Effusions &Edema

新操作：抑制 Vasc 渗漏可预防炭疽胸腔积液

• 批准号: 7645448
• 负责人: Joanne Chan
• 金额: $ 23.94万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7645448
• 关键词: Acute; Adult; Anthrax disease; Antibiotics; Attenuated; Biological Assay; Blood Vessels; Cardiovascular Physiology; Case Study; Cavia; Cessation of life; Chemicals; Chest; Clinical; Data; Defect; Drainage procedure; Dyes; Edema; Embryo; Endothelial Cells; Extravasation; Hospitals; Human; Image; Injection of therapeutic agent; Intensive Care; Life; Liquid substance; Lung; Measures; Mediastinum; Membrane; Modeling; Mus; Numbers; Organ; Oryctolagus cuniculus; Pathway interactions; Phosphorylation; Pleural; Pleural effusion disorder; Rattus; Skin; Staging; Testing; Therapeutic; Time; Tissues; Toxic effect; Toxin; VEGFR inhibition; Vascular Endothelial Growth Factor Receptor; Vascular Endothelial Growth Factors; Vascular Permeabilities; Zebrafish; abstracting; age related; anthrax lethal factor; anthrax toxin; attenuation; bevacizumab; cancer therapy; inhibitor/antagonist; macula; nonhuman primate; protective effect; research study

1. Abstract Human case studies have described pleural effusions and the presence of a widened mediastinum on chest x-rays as the most common clinical features of anthrax disease. Of the 11 people who developed acute anthrax disease in 2001, 6 survived due to the intensive care received at hospitals that included fluid drainage from the lung, and treatment with antibiotics. Increased vascular permeability has been strongly implicated in anthrax toxin induced tissue edema in a large number of mammalian models (non-human primates, rabbits, guinea pigs, rats, mice). The importance of blood vessels and endothelial cells in anthrax toxicity has been difficult to investigate due to the inability to observe progressive vascular changes without sacrificing the mammalian host. Therefore, we developed the transparent zebrafish embryo as a model to facilitate live imaging of anthrax lethal toxin action on intact blood vessels. We observed that lethal toxin induced increased vascular permeability as an early consequence leading to progressive defects in cardiovascular function. Since vascular permeability is regulated by the vascular endothelial growth factor, also called the vascular permeability factor (VEGFNPF), we employed chemical inhibitors to block this pathway to reduce toxin effects, achieving remarkable levels of attenuation. These data were confirmed using an established vascular permeability assay in adult mouse skin microvasculature termed the Miles Assay. Here, inhibition of the VEGFNPF pathway reduced lethal toxin induced vascular leakage as measured by a colorimetric dye. Since the Fischer 344 rat is an established anthrax toxin model where vascular defects have been observed, we are currently employing this model to test the hypothesis that blocking the VEGF pathway can yield protective effects against lethal toxin action as measured by increased survival time. This model is extremely sensitive to lethal toxin challenge, typically inducing death in about 45-60 minutes. In our experiments, we observe vascular defects in multiple organs and extensive pleural effusions at late stages during toxin challenge. Analysis of VEGFR phosphorylation levels in the lung demonstrated increased activation of this pathway post toxin injection, suggesting that inhibitors of the VEGF pathway could attenuate toxin effects. Since anti-VEGF therapies are already in clinical use for cancer therapy and for the treatment of age-related vascularized macula degeneration, further testing of their usefulness as an anti-anthrax therapeutic could be expedited. This approach may be combined with antibiotics or anti-toxins to increase the therapeutic window for the effective treatment of anthrax disease.

1.摘要 人类病例研究已经描述了胸腔积液和纵隔扩大的存在， 胸部X光检查为炭疽病最常见的临床特征。在11名患有急性 在2001年的炭疽病中，由于在医院接受了包括液体引流在内的重症监护， 从肺部取出，并用抗生素治疗血管渗透性增加与 炭疽毒素在大量哺乳动物模型（非人灵长类，兔， 豚鼠、大鼠、小鼠）。血管和内皮细胞在炭疽毒性中的重要性已经被 由于无法观察到进行性血管变化而不牺牲 哺乳动物宿主因此，我们开发了透明的斑马鱼胚胎作为模型，以方便活体 炭疽致命毒素作用于完整血管的成像。我们观察到致死毒素诱导的 血管渗透性作为早期结果导致心血管功能的进行性缺陷。以来 血管通透性受血管内皮生长因子（也称为血管内皮生长因子）调节。 由于VEGF-NPF是血管通透性因子，我们采用化学抑制剂阻断该途径以减少毒素作用， 实现了显著的衰减水平。这些数据得到了证实，使用一个建立的血管 在成年小鼠皮肤微脉管系统中的渗透性测定称为Miles测定。在这里， VEGFNPF途径减少致死毒素诱导的血管渗漏，如通过比色染料测量的。以来 Fischer 344大鼠是已建立的炭疽毒素模型，其中观察到血管缺陷，我们 目前使用该模型来测试阻断VEGF通路可以产生保护性的假设， 通过增加的存活时间来测量对致死毒素作用的影响。该模型对 致死毒素攻击，通常在约45-60分钟内诱导死亡。在实验中，我们观察到 在毒素激发过程中，晚期出现多器官血管缺损和广泛胸腔积液。 对肺中VEGFR磷酸化水平的分析表明， 毒素注射，表明VEGF途径的抑制剂可以减弱毒素作用。由于抗VEGF 这些疗法已经在临床上用于癌症治疗和用于治疗与年龄相关的血管化 黄斑变性，可以加快进一步测试它们作为抗炭疽治疗剂的有用性。这 这种方法可以与抗生素或抗毒素结合，以增加有效治疗的治疗窗口。 炭疽病的治疗。