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

1.摘要 人类病例研究描述了胸腔积液和胸腔内纵隔增宽。 胸部X光是炭疽病最常见的临床特征。在11名患上急性胰腺炎的人中 炭疽病2001年，有6人幸存下来，这是因为医院接受了包括液体排出在内的重症监护 从肺中取出，并用抗生素治疗。血管通透性的增加强烈地与 炭疽毒素在大量哺乳动物模型(非人灵长类动物，兔子， 豚鼠、大鼠、小鼠)。血管和内皮细胞在炭疽毒性中的重要性已被 难以调查，因为无法观察到进行性血管变化而不牺牲 哺乳动物宿主。因此，我们开发了透明斑马鱼胚胎作为模型，以方便生活 炭疽毒素对完整血管的致死作用的成像。我们观察到致死毒素诱导的增加 血管通透性是导致心血管功能进行性缺陷的早期后果。自.以来 血管通透性由血管内皮生长因子调节，也称为血管 渗透因子(VEGFNPF)，我们使用化学抑制剂来阻断这一途径，以减少毒素的影响， 达到了显著的衰减水平。这些数据是用已建立的血管 成年小鼠皮肤微血管通透性测定，称为迈尔斯试验。在这里，抑制 通过比色染料检测，VEGFNPF途径减少了致死毒素诱导的血管渗漏。自.以来 Fischer 344大鼠是一种已建立的炭疽毒素模型，已观察到血管缺陷，我们是 目前正在使用这一模型来测试阻断血管内皮生长因子途径可以产生保护作用的假设 通过延长存活时间来衡量对致命毒素作用的影响。这款机型对 致命的毒素挑战，通常在大约45-60分钟内导致死亡。在我们的实验中，我们观察到 在毒素攻击的晚期，多个器官的血管缺陷和广泛的胸腔积液。 对肺中VEGFR磷酸化水平的分析表明，该通路在肺损伤后被激活 毒素注射，提示血管内皮生长因子途径的抑制剂可以减弱毒素的影响。因为抗血管内皮生长因子 治疗方法已经在临床上用于癌症治疗和年龄相关性血管化的治疗。 对于黄斑变性，可以加快对其作为抗炭疽治疗药物的有效性的进一步测试。这 可采用联合抗生素或抗毒素的方法来增加治疗窗的有效性 炭疽病的治疗。

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.