Development of small molecule cGAS inhibitors for repression of dsDNA-triggered interferon expression

环状GMP-AMP合成酶(CGAS)是胞质dsdna的主要感受器，产生环状二核苷酸。 CGAMP，第二信使，启动髓系细胞亚群中细胞因子的产生 负责提供先天免疫力。胞浆dsDNA的异常会导致炎症性疾病， 提示抑制cGAS可能在治疗上是有益的。我们最近开发了一种质量- 基于小鼠cGAS和识别小分子抑制剂的光谱高通量筛选(HTS) 这在小鼠细胞试验中产生了第一个活性和特异性的cGAS抑制剂，尽管没有抑制作用。 人类细胞中的活动。我们现在开发了一种更快、更具成本效益的HTS来识别人类 CGAS抑制剂使用化学发光和筛选300,000个化合物。后继药物 化学优化确定了有效和特异的抑制人cGAS活性的主要干扰素- 产生细胞类型，包括原代巨噬细胞和外周血单核细胞。我们还解决了化合物的共晶结构 与人类cGAS的抑制剂，为领先的建议结构和计算引导的优化路径 抑制剂。我们建议通过扩展寻找新的热门化合物来获得更多的药物支架 药物库筛选继续支持我们的药物化学项目。使用最强大和最强大的 特定的抑制剂，我们希望表征它们的抑制效果和通路的特异性在更多样化 单元格范围。我们的长期目标是开发治疗cGAS调节失调相关疾病的疗法。 本方案分为三个目标：(1)利用高温超导技术寻找新的化学支架并应用 化学信息学分析和药物化学命中优化。我们将利用我们新成立的和 用于鉴定人cGAS抑制剂的有效HTS方法筛选新的100,000个可用的文库 化合物。新的热门化合物将优先进行进一步的衍生化，以优化效力和类药物 特点。(2)结构/计算指导下的新型脚手架和引线优化设计 人类cGAS抑制剂。我们将利用从抑制剂-cGAS共晶结构中获得的见解来设计， 合成并测试衍生物，以探索最有效、最有前途的类药物cGAS抑制剂(S)。(3) 建立新的细胞验证分析方法来鉴定有效和高选择性的cGAs 抑制剂。我们建议评估和验证新的和最近发现的抑制剂通过评估它们的 使用已建立的和新的包括非髓系细胞检测的有效性、选择性和生物相容性 染色体不稳定的癌细胞系、原代髓系细胞和患者来源的髓系细胞。 虽然最初被发现是作为抗病毒活性的中央dsDNA传感器，但cGAS也正在成为 肥胖、神经退行性疾病、肿瘤发生和癌症转移。功能齐全、经过验证、 在研究cGAS刺痛生物学的社区中需要有效和特定的cGAS抑制剂 治疗cGAS相关炎症性疾病！

Cyclic GMP-AMP synthase (cGAS) is the primary sensor for cytosolic dsDNA, producing the cyclic dinucleotide cGAMP, a second messenger initiating cytokine production in subsets of myeloid-lineage cell types and responsible for providing innate immunity. Aberrant cytosolic dsDNA contributes to inflammatory diseases, suggesting that inhibition of cGAS may be therapeutically beneficial. We recently developed a mass- spectrometry-based high throughput screen (HTS) using mouse cGAS and identified small-molecule inhibitors that yielded the first active and specific inhibitors of cGAS in mouse cellular assays, albeit with no inhibitory activity in human cells. We now developed a faster and more cost effective HTS for identification of human cGAS inhibitors using chemiluminescence and screened 300,000 compounds. Subsequent medicinal chemistry optimization identified potent and specific inhibitors for human cGAS active in major interferon- producing cell types including primary macrophages and PBMCs. We have also solved co-crystal structures of inhibitors with human cGAS, suggesting structure- and computational-guided optimization path for the lead inhibitors. We propose to identify new hit compounds to access additional drug scaffolds through extended drug library screening to continue supporting our medicinal chemistry program. Using the most potent and specific inhibitors, we wish to characterize their inhibitory effect and pathway specificity in a more diverse range of cells. Our long-term goal is to develop therapeutics for cGAS-dysregulation associated diseases. This proposal is organized in 3 aims: (1) Identify new chemical scaffolds by HTS and apply cheminformatic analysis and medicinal chemistry hit optimization. We will use our newly established and validated HTS method for identification of human cGAS inhibitors to screen a newly available library of 100,000 compounds. New hit compounds will be prioritized for further derivatization to optimize potency and drug-like characteristics. (2) Structure/computation-guided design for optimization of new scaffolds and lead human cGAS inhibitors. We will use the insights gained from inhibitor-cGAS co-crystal structures to design, synthesize, and test derivatives to probe for the most potent, and promising drug-like cGAS inhibitor(s). (3) Develop new cellular validation assays for the identification of potent and highly selective cGAS inhibitors. We propose to evaluate and validate new and recently identified inhibitors by assessing their efficacy, selectivity, and biocompatibility using established and new cellular assays including non-myeloid cancer cell lines with chromosomal instability, primary myeloid cells, and patient-derived myeloid cells. Although initially discovered as central dsDNA sensor for antiviral activity, cGAS is also emerging as a player in obesity, neurodegenerative diseases, tumorigenesis, and cancer metastasis. Well-characterized, validated, potent, and specific cGAS inhibitors are needed in the community studying cGAS-STING biology as well as for treating cGAS-related inflammatory diseases!