Gram-Negative Sepsis: Pharmacophore-Based Therapeutics

革兰氏阴性脓毒症：基于药效团的治疗

• 批准号: 6784604
• 负责人: Sunil A David
• 金额: $ 36万
• 依托单位: UNIVERSITY OF KANSAS LAWRENCE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6784604
• 关键词: alkylation; biological signal transduction; cations; clinical research; combinatorial chemistry; computer simulation; cooperative study; disease /disorder model; drug discovery /isolation; endotoxins; high throughput technology; human tissue; hydrogen bond; interleukin 1; intermolecular interaction; laboratory mouse; lipopolysaccharides; microorganism disease chemotherapy; molecular site; nitric oxide; polyamines; septic shock; septicemia; tumor necrosis factor alpha

DESCRIPTION (provided by applicant): Gram-negative sepsis, a common and serious sequel of systemic bacterial infections is the leading cause of mortality, accounting for some 200,000 fatalities annually in the US alone. The pathogenesis of Gram-negative septic shock is due to the host response to endotoxins, or lipopolysaccharides (LPS), present on the surface of gram-negative bacteria. There are, to date, no FDA-approved therapeutic options targeting the endotoxin itself to prevent or treat this disease. We have shown that relatively simple, and synthetically easily accessible molecules of the lipopolyamine class specifically bind to LPS and neutralize its toxicity both in vitro and in animal models of septic shock. The affinity of the lipopolyamines toward LPS, however, is relatively weak (2-10 (M). In this proposal, our goal is to identify high-affinity LPS binders with nonlipopolyamine scaffolds as novel leads for the therapy of Gram-negative sepsis. A focused library of ~6000 compounds, each possessing the primary pharmacophore for LPS binding will be screened using a well-established fluorescence displacement method implemented in HTS formats. Binding, however, does not necessarily manifest in neutralization of LPS toxicity. For neutralization, an additional, appropriately positioned long-chain aliphatic group is essential. High-affinity binders ("hits") identified in HTS will be alkylated appropriately to generate LPS-neutralizing compounds (sequestrants). In in vitro assays, the potency of lead compounds in inhibiting the release of LPS-mediated proinflammatory cytokines such as tumor necrosis factor will be characterized. In a select subset of promising leads identified in the screens described above, we will verify that the mechanism of action of inhibition of LPS toxicity is via its sequestration by showing that relevant upstream cell-signaling events are blocked. The protective effects of particularly promising molecules will then be examined in two well-established murine models of gram-negative sepsis. We will systematically evaluate the toxicity of the test-compounds in a carefully chosen panel of in vitro assays. Molecular modeling techniques will be applied in an effort to correlate experimentally observed binding affinities of the test compounds with features of molecular interaction such as binding geometry, H-bonds, electrostatic, hydrophobic, and van der Waals contributions to the free energy of binding. Based on the data from the primary screen, in silico modeling, and biological assays, we will synthesize a series of analogues around promising leads using a combination of focused virtual library screening and classical medicinal chemistry approaches.

描述（由申请人提供）：革兰氏阴性败血症，全身细菌感染的常见和严重的续集是死亡率的主要原因，仅在美国，每年约有200,000次死亡。革兰氏阴性败血性休克的发病机理是由于宿主对内毒素或脂多糖（LPS）的反应，存在于革兰氏阴性细菌的表面上。迄今为止，没有针对内毒素本身来预防或治疗这种疾病的FDA批准的治疗方案。我们已经表明，脂蛋白类别类别的相对简单和合成易于访问的分子特异性结合了LPS并在体外和败血性休克的动物模型中中和其毒性。 The affinity of the lipopolyamines toward LPS, however, is relatively weak (2-10 (M). In this proposal, our goal is to identify high-affinity LPS binders with nonlipopolyamine scaffolds as novel leads for the therapy of Gram-negative sepsis. A focused library of ~6000 compounds, each possessing the primary pharmacophore for LPS binding will be screened using a well-established fluorescence但是，以HTS形式实施的方法。在抑制LPS介导的促炎细胞因子（例如肿瘤坏死因子）中的化合物将在上述屏幕中的某些有希望的潜在客户子集中进行表征，我们将通过显示相关的Upstream CellStream Cellsignal-Signal-Signal-Spretants blocked，我们将通过显示序列抑制LPS毒性的作用机制。然后，将在革兰氏阴性败血症的两个公认的鼠模型中检查特别有希望的分子的保护作用。我们将系统地评估精心选择的体外测定面板中测试化合物的毒性。将应用分子建模技术，以将测试化合物的实验观察到的结合亲和力与分子相互作用的特征相关联，例如结合几何，H键，静电，疏水性和范德华对结合能量的自由能有助于。基于主要屏幕的数据，在计算机建模和生物学测定中，我们将使用集中的虚拟库筛选和经典的药物化学方法结合围绕有希望的潜在客户进行一系列类似物。