Mechanisms regulating the biosynthesis and signaling of oxylipins

项目总结 氧磷脂是从多不饱和脂肪酸中提取的含氧生物活性脂类，具有多种不同的 在健康和疾病方面具有不可或缺的功能，包括炎症、癌症和心血管疾病。氧磷脂 是由环氧合酶(COX)按需合成的短暂的局部作用的信号分子， 脂氧合酶(LOX)，或细胞色素P450单加氧酶。脂质组学的进展导致了这种检测 氧化脂的疾病特异性变化。尽管对氧化脂质中疾病特异性变化的识别已经 用于疾病诊断、预后或治疗的力量，将脂类研究转化为 由于对氧磷脂缺乏生物学上的了解，临床仍然具有挑战性。为了更好地理解 疾病特定变化的临床相关性，我们确定了我们知识中的关键差距，需要 讨论，包括1)什么机制调节多种氧脂的协调合成导致 细胞特有的氧化脂质模式；以及2)个体氧化脂质信号是如何整合到 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 破译负责合成和发挥单个氧化脂质功能的信号机制 了解他们在疾病中的变化所产生的功能后果。没有更多机械的洞察力 对于疾病特异性氧化脂质的变化，新的氧化脂质不太可能有效地用于临床 目的。血小板是研究氧脂生物学的理想模型系统，因为它们能产生纳分子 COX和12(S)-脂氧合酶(12-LOX)的大约15个加氧脂的水平，并提供了一个简化的模型 研究氧脂失调的生物学后果。在这份提案中，我们将重点放在 12-LOX及其花生四烯酸(AA)代谢产物12-HETE，具有广泛的临床和生物学意义 意义。然而，由于对12-HETE的功能缺乏共识，12-HETE的作用机制。 LOX有助于炎症、癌症进展和凝血是有争议的，并代表着大量的 知识鸿沟。这项提案将研究12-LOX和12-HETE作为典型例子，以解决其在 疾病，并开发工具来表征氧磷脂的功能，通过使用基因编辑的人 巨核细胞，已被证明是捐赠者来源的血小板的忠实概括。我们的短期计划 目标是1)确定用于释放和输送底物到12-LOX和2)的细胞内机制 确定12-羟色胺在血小板中激活的下游信号通路(S)。我们的研究将提供 对氧磷脂合成和功能的机械理解有价值的见解，最终可能有助于 在为广泛的疾病开发新的治疗方法方面。

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.