Therapeutic Small Molecule Modulators of G beta gama Signaling

描述（由申请人提供）：G蛋白亚基在G蛋白偶联受体（GPCR）介导的信号转导过程中发挥核心作用。它们在7 TM受体的活化中充当辅因子，并在向细胞内靶标的信号传导中发挥直接作用。从治疗的角度来看，GPCR信号传导是极其重要的;事实上，大多数市售药物靶向GPCR的受体组分。迄今为止发展较少的是细胞内亚基信号传导的选择性操纵，其可以允许同时调节7 TM受体下游的多个信号传导途径。因此，亚基信号传导的靶向调节剂的商业化将对药物发现范式产生巨大影响。罗切斯特大学医学中心（URMC）的Alan Smrcka、Burns Blaxall和Jean Bidlack教授开发了一种新的策略，用于选择性操纵G蛋白亚基信号传导，使用小分子量化合物阻断G蛋白亚基与功能蛋白质伴侣的结合。他们已经证明这些化合物在心力衰竭、炎症和吗啡依赖性镇痛的动物模型中是有效的。Califia Bio，Inc.正在与URMC团队合作，将这些最初的命中分子开发成先进的化学先导。这些电极导线最终将进展为治疗心血管疾病和慢性疼痛的临床研究。目前的URMC命中分子是从NCI化合物集合中鉴定的，并且缺乏药物样特征以及明确的知识产权保护，这阻碍了它们的商业开发。为了进一步开发亚基蛋白相互作用的新型小分子抑制剂，Califia Bio将利用：1）由URMC在高通量筛选活动中收集的SAR，2）先前鉴定的与亚基热点结合的小螺旋肽抑制剂的X射线晶体结构，3）与相同热点结合的弱亲和力小分子配体的X射线晶体结构，和4）专门靶向的可逆抑制剂，旨在阻断热点中的关键活性半胱氨酸。在其初始设计后，潜在的抑制剂将对接到现有的晶体结构中，并在合成前通过评估其药物样特征和潜在的ADMET问题（使用Optimantine Ltd的专有软件）进行进一步分类。将使用主要ELISA结合试验对化合物进行优先排序，然后进行抑制PLC活化和GRK 2 G结合抑制的次要试验。β-肾上腺素能受体（BAR）功能障碍代表心力衰竭的标志性异常，并且已经证明干扰G蛋白介导的GRK 2活性可以逆转（BAR）过度刺激的作用。将确定可获得专利的先导化合物系列，并利用上述体外试验优化该系列的效价和选定的ADME特性。在第二阶段，将建立动物模型的疗效，并优化ADME特性，以允许用于治疗心力衰竭和慢性疼痛的潜在疗法的先进临床前开发。 公共卫生相关性：该I期SBIR提案旨在发现治疗心力衰竭的潜在小分子疗法。所涉及的机制也可能对提高用于治疗慢性疼痛的阿片类药物的疗效和减轻其副作用感兴趣。据估计，心力衰竭是一个价值20亿美元的药物市场，其中存在巨大的未满足的治疗需求，在美国约有570万患者，每年有670，000例新病例。在终末期心力衰竭中，只有一半的患者能存活一年，唯一成功的治疗方法是心脏移植，每年只有大约2000名患者有幸接受新的心脏。

DESCRIPTION (provided by applicant): G protein subunits play a central role in G-protein coupled receptor (GPCR)-mediated signal transduction processes. They act as cofactors in the activation of 7TM receptors and play direct roles in signaling to intracellular targets. GPCR signaling is extremely significant from a therapeutic standpoint; indeed, the majority of marketed pharmaceuticals target the receptor components of GPCRs. Less developed to date is the selective manipulation of intracellular subunit signaling, which could allow for the simultaneous modulation of multiple signaling pathways downstream of 7TM receptors. The commercialization of targeted modulators of subunit signaling would therefore have a tremendous impact on drug discovery paradigms. Professors Alan Smrcka, Burns Blaxall and Jean Bidlack at the University of Rochester Medical Center (URMC) have developed a novel strategy for the selective manipulation of G-protein subunit signaling that blocks - subunit binding to functional protein partners using small molecular weight compounds. They have demonstrated that these compounds are efficacious in animal models of heart failure, inflammation, and morphine-dependent analgesia. Califia Bio, Inc. is collaborating with the URMC team to develop these initial hit molecules into advanced chemical leads. These leads will ultimately be progressed into clinical studies for the treatment of cardiovascular disease and chronic pain. The current URMC hit molecules were identified from the NCI compound collection and lack drug-like characteristics as well as definitive intellectual property protection, which hampers their commercial development. In order to further develop novel small molecule inhibitors of subunit protein interactions, Califia Bio will utilize: 1) SAR gathered by URMC in high- throughput screening campaigns, 2) an X-ray crystal structure of previously identified small helical peptide inhibitor that binds to the subunit hot spot, 3) an X-ray crystal structure of a weak affinity small molecule ligand that binds to the same hot spot, and 4) specifically targeted reversible inhibitors designed to block a key active cysteine in the hot spot. After their initial design, potential inhibitors will be docked into the existing crystal structures and further triaged before synthesis by assessing their drug-like character and potential ADMET issues with proprietary software from Optibrium Ltd. A primary ELISA binding assay will be used to prioritize compounds, followed by secondary assays for inhibition of PLC activation and GRK2 G binding inhibition. -adrenergic receptor (BAR) dysfunction represents a hallmark abnormality of heart failure and interference of G-protein mediated GRK2 activity has been demonstrated to reverse the effects of (BAR) overstimulation. A patentable lead series will be identified, and the potency and selected ADME properties of this series will be optimized utilizing the above mentioned in vitro assays. In phase two, efficacy in animal models will be established and ADME properties will be optimized to allow for advanced preclinical development of potential therapeutics for treatment of heart failure and chronic pain. PUBLIC HEALTH RELEVANCE: This Phase I SBIR proposal is aimed at the discovery of potential small molecule therapeutics to treat heart failure. The mechanism involved may also be of interest for enhancing the efficacy and lessening the side effects of opioids used to treat chronic pain. Heart failure is estimated to be a $2 billion dollar drug market where there is great unmet therapeutic need, with approximately 5.7 million patients in the US, and 670,000 new cases per year. In end stage heart failure, only one half of patients will survive one year, and the only successful treatment is heart transplant, where only approximately 2000 patients per year are lucky enough to receive new hearts.