NIH Minority Supplement for Kerry A. Smith to GM120357

摘要 心血管疾病(CVD)是世界范围内的头号死亡原因。高水平的低密度 脂蛋白(LDL)，临床上称为高胆固醇血症或高脂血症，与 心血管疾病。尽管他汀类药物对许多高胆固醇血症患者非常成功，但大约 由于他汀类药物的不良反应，20%的患者无法达到目标低密度脂蛋白水平。 枯草杆菌前蛋白转换酶9(PCSK9)在胆固醇稳态中的重要调节作用 是治疗高胆固醇血症的有效新靶点。抑制肿瘤细胞生长的化合物 PCSK9的作用可以是单独治疗，也可以作为他汀类药物在 高胆固醇血症治疗方案。从发现PCSK9基因到发现 两种针对分泌的PCSK9蛋白的抗体药物的批准，这是对 PCSK9的意义和重要性。然而，对PCSK9基本生物学的了解还远远滞后 在临床发展的背后。这份来自华盛顿大学唐、阿蒂和李的实验室的合作提案- 麦迪逊计划研究新的小分子的生物学机制和蛋白质靶标，这些小分子可以 导致PCSK9蛋白的选择性降解。我们将通过做好三个方面的工作来实现这些目标 具体目标：1)开发灵敏的检测方法以评估其效力、细胞毒性、选择性和代谢。 新型小分子PCSK9调节剂的稳定性；2)阐明小分子PCSK9的作用机理 PCSK9分子调节子从转录、翻译、翻译后迭代的方法 修饰和降解，以分泌；3)确定小分子PCSK9的直接结合伙伴 带有适当化学探针的调节剂，研究该结合伙伴的生理功能，以及 评估其治疗潜力。这一提议是创新的，因为我们的小分子针对PCSK9 不同于已知的生物试剂如抗体和已知的天然药物的调控途径 其中大多数下调PCSK9的转录。根据我们的初步结果，我们 假设我们的化合物通过选择性地促进翻译后反应来调节PCSK9的稳定性 PCSK9的降解。我们提出了多个跨学科的方法来检查我们的小 分子影响转录、翻译、蛋白质加工和降解，以及蛋白质的分泌途径 PCSK9。这项拟议的研究将产生新的小分子工具，可以改变我们研究血脂调节的方式 此外，我们还发现了治疗高胆固醇血症的新的生物靶点和途径。

ABSTRACT Cardiovascular diseases (CVD) is the number one cause of death world-wide. High levels of low density lipoprotein (LDL), clinically known as hypercholesterolemia or hyperlipidemia, are strongly associated with CVD. Although statin therapy has been very successful for many patients with hypercholesterolemia, about 20% of patients are not able to achieve target LDL levels due to the adverse effects of statin therapy. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a major regulatory role in cholesterol homeostasis and is a validated new therapeutic target for the treatment of hypercholesterolemia. Compounds that inhibit the action of PCSK9 can be stand-alone treatments or function as synergistic agents with statins in a hypercholesterolemia treatment regimen. It took only 12 years from the discovery of the PCSK9 gene to the approval of two antibody drugs against the secreted PCSK9 protein, which is a strong testimony for the significance and importance of PCSK9. However, the understanding of the basic biology of PCSK9 lags far behind the clinical development. This collaborative proposal from laboratories of Tang, Attie, and Li at UW- Madison is intended to study the biological mechanism and protein target of novel small molecules that can lead to selective degradation of PCSK9 protein. We will accomplish these objectives by completing three specific aims: 1) Develop sensitive assays to evaluate the potency, cytotoxicity, selectivity, and metabolic stability of novel small molecule PCSK9 modulators; 2) Elucidate the mechanism of action of our small molecule PCSK9 modulators by an iterative approach from transcription, translation, posttranslational modification and degradation, to secretion; 3) Identify the direct binding partner of our small molecule PCSK9 modulators with appropriate chemical probes, investigate the physiological function of this binding partner, and evaluate its therapeutic potential. This proposal is innovative because our small molecules target PCSK9 regulation pathways that are distinct from known biological reagents such as antibodies and known natural products, most of which down regulate the transcription of PCSK9. Based on our preliminary results, we hypothesize that our compounds regulate the stability of PCSK9 by selectively promoting the post-translational degradation of PCSK9. We proposed multiple interdisciplinary approaches to examine how our small molecules affect transcription, translation, protein processing and degradation, and the secretory pathway of PCSK9. The proposed study will yield novel small molecule tools that can change how we study lipid regulating pathways and also uncover new biological targets and pathways for treating hypercholesterolemia.