Mechanisms regulating the biosynthesis and signaling of oxylipins

项目摘要 氧脂素是衍生自多不饱和脂肪酸的含氧生物活性脂质，其具有多种 在健康和疾病中的整体功能，包括炎症，癌症和心血管疾病。氧化脂 是短暂的、局部作用的信号分子，由环氧合酶（考克斯）按需合成， 脂氧合酶（LOX）或细胞色素P450单加氧酶。脂质组学的进步已经导致了检测 疾病特异性的氧化脂质变化。虽然确定疾病特异性变化的氧脂素， 用于疾病诊断、预后或治疗的能力，将脂质组学研究转化为 由于缺乏对氧脂素的生物学理解，临床仍然具有挑战性。更好地了解 疾病特异性变化的临床相关性，我们确定了我们知识中的关键空白，需要 解决，包括1）什么机制调节多种氧脂素的协调合成， 细胞特异性氧化脂蛋白模式;以及2）从个体氧化脂蛋白引起的信号如何整合到 生物功能。为了解决我们知识中的这些差距，我们研究计划的长期目标是 破译负责单个氧脂素合成和功能的信号机制， 了解它们在疾病中的改变的功能后果。如果没有进一步的机械见解 尽管将氧脂素的疾病特异性变化纳入临床研究，但新的氧脂素不太可能有效地靶向临床应用。 目的血小板是研究氧脂素生物学的理想模型系统，因为它们产生纳摩尔的 水平的大约15个氧化脂质从考克斯和12（S）-脂氧合酶（12-LOX），并提供了一个简化的模型 来研究氧脂素失调的生物学后果。在本提案中，我们将重点讨论 12-LOX及其花生四烯酸（AA）衍生代谢产物12-HETE具有广泛的临床和生物学活性， 意义然而，由于对12-HETE的功能缺乏共识，12-HETE的作用机制尚不清楚。 LOX有助于炎症，癌症进展，凝血是有争议的，代表了实质性的 知识差距。本提案将研究12-LOX和12-HETE作为原型实例，以解决其在 疾病，并开发工具，通过使用基因编辑的人类 巨核细胞，其已显示忠实地再现供体来源的血小板。我们的短期 目的是1）确定用于释放和递送底物至12-LOX的细胞内机制，和2） 鉴定血小板中12-HETE激活的下游信号通路。我们的研究将提供 对氧脂素合成和功能的机械理解的有价值的见解， 在开发治疗多种疾病的新方法方面。

PROJECT SUMMARY Oxylipins are oxygenated bioactive lipids derived from polyunsaturated fatty acids that have diverse and integral functions in health and disease, including inflammation, cancer, and cardiovascular diseases. Oxylipins are short-lived, locally acting signaling molecules that are synthesized on demand by cyclooxygenases (COX), lipoxygenases (LOX), or cytochrome P450 monooxygenases. Advances in lipidomics have led to the detection of disease-specific changes in oxylipins. Although the identification of disease-specific changes in oxylipins has the power to be used for disease diagnosis, prognosis, or treatment, the translation of lipidomic studies into the clinic remains challenging due to a lack of biological understanding of oxylipins. To better understand the clinical relevance of disease-specific changes, we identified critical gaps in our knowledge that need to be addressed, including 1) what mechanisms regulate the coordinated synthesis of multiple oxylipins leading to cell-specific oxylipin patterns; and 2) how the signals elicited from individuals oxylipins are integrated into biological functions. To address these gaps in our knowledge, the long-term goal of our research program is to decipher the signaling mechanism responsible for the synthesis and function of individual oxylipins to understand the functional consequence of their alterations in diseases. Without further mechanistic insights into disease-specific changes in oxylipins, it is unlikely novel oxylipins will be effectively targeted for clinical purposes. Platelets are the ideal model system to study oxylipin biology because they produce nanomolar levels of approximately 15 oxylipins from COX and 12(S)-lipoxygenase (12-LOX) and offer a simplified model to study the biological consequences of oxylipin dysregulation. In this proposal, we will focus on the function of 12-LOX and its arachidonic acid (AA)-derived metabolite, 12-HETE, which have broad clinical and biological significance. However, due to the lack of consensus on the function of 12-HETE, the mechanism by which 12- LOX contributes to inflammation, cancer progression, and clotting is controversial and represents a substantial knowledge gap. This proposal will study 12-LOX and 12-HETE as a prototypical examples to address its role in disease, and develop tools to characterize the function of oxylipins by using gene-edited human megakaryocytes, which have been shown to faithfully recapitulate the donor-derived platelets. Our short-term goals are to 1) determine the intracellular mechanisms used to release and deliver substrate to 12-LOX and 2) identify the downstream signaling pathway(s) activated by 12-HETE in platelets. Our studies will provide valuable insight into the mechanistic understanding of oxylipin synthesis and function that could ultimately aid in developing new therapeutic approaches for a broad range of diseases.