Investigating the impact of a fatty acid-cRel inflammatory circuit in atherosclerosis

R01：研究脂肪酸-cRel 炎症回路对动脉粥样硬化的影响 摘要/总结 这笔资助的目的是了解炎症和脂质代谢如何通过体内的回路联系起来 巨噬细胞，以及这些回路是否影响心脏代谢疾病。尽管血脂受到干扰 体内平衡被认为与许多人类疾病的炎症有关，我们的 对这些过程“如何”和“为何”密切相关的理解仍然有限。最近的工作已经揭示 促炎信号可以重新编程巨噬细胞的脂质代谢状态。也已经明朗起来 巨噬细胞的炎症机制可以感知脂质稳态的扰动，从而 诱导和调节炎症反应。因此，脂质稳态和炎症是相互关联的， 一个方面的扰动会影响另一个方面。在这个提案中，我们结合了先进的分析质谱法—— 基于炎症遗传模型的方法，其目标是定义机制 炎症驱动脂质组的重新编程（反之亦然）。具体目标 1 是确定 单不饱和脂肪酸（MUFA）稳态的改变调节炎症的机制 激活巨噬细胞。具体来说，我们将继续探索阻断 MUFA 从头合成的发现 通过 NF-κB 成员 cRel 增强炎症反应。通过结合转录组学，ATAC- Seq 和 ChIP-Seq 方法，我们将检验 MUFA 合成调节炎症功能的假设 通过专门控制 cRel 和重新编程表观基因组。具体目标 2 重点推进 我们对巨噬细胞中脂质代谢重编程如何发生的理解，并确定其程度 体内单核细胞和巨噬细胞的脂质代谢重新编程。通过应用先进的 正常、炎症和血脂异常条件下组织驻留巨噬细胞的分析技术， 我们将确定激活信号和脂质环境线索是否可以诱导或塑造脂质代谢 体内重编程。我们还进一步了解抗炎信号或内质网应激信号如何 被整合到代谢重编程的过程中。具体目标 3 是确定 SCD 酶对小鼠血脂异常、慢性炎症和动脉粥样硬化的影响。 SCD 蛋白已被 据报道可增强和减弱动脉粥样硬化形成。我们怀疑这是由于复杂的因素造成的 有多个SCD。为此，我们询问巨噬细胞中 SCD1 和 SCD2 的联合丢失是否特异 加剧炎症、血脂异常和动脉粥样硬化。相反，可以强制执行 SCD 表达式 单核细胞和巨噬细胞可以预防疾病。同样，cRel 的缺失是否会减轻炎症和 西方饮食引起的动脉粥样硬化形成。我们期望我们提出的研究将在一定程度上定义 分子水平，为什么巨噬细胞脂质稳态失调会导致炎症，以及炎症如何发生 影响心血管疾病中的巨噬细胞胆固醇代谢。

R01: Investigating the impact of a fatty acid–cRel inflammatory circuit in atherosclerosis ABSTRACT/SUMMARY The objective of this grant to is to understand how inflammation and lipid metabolism are linked via circuits within macrophages, and whether these circuits influence cardiometabolic disease. Although perturbations in lipid homeostasis are recognized to be associated with inflammation in a number of human diseases, our understanding of “how” and “why” the processes are intimately linked remains limited. Recent work has revealed that pro-inflammatory signals can reprogram the lipid metabolic state of macrophages. It has also become clear that perturbations in lipid homeostasis can be sensed by the inflammatory machinery of macrophages so as to induce and to regulate inflammatory responses. Thus, lipid homeostasis and inflammation are interconnected, and perturbations in one affect the other. In this proposal, we combine advanced analytical mass spectrometry– based approaches with genetic models of inflammation, with the goal of defining mechanisms by which inflammation drives reprogramming of the lipidome (and vice versa). Specific Aim 1 is to determine the mechanisms by which alterations in monounsaturated fatty acid (MUFA) homeostasis regulate inflammation in activated macrophages. Specifically, we will pursue our discovery that blocking de novo MUFA synthesis potentiates inflammatory responses via the NF-κB member cRel. Using a combination of transcriptomics, ATAC- Seq, and ChIP-Seq approaches, we will test the hypothesis that MUFA synthesis regulates inflammatory function by specifically controlling cRel and the reprogramming the epigenome. Specific Aim 2 is focused on advancing our understanding of how reprogramming of lipid metabolism occurs in macrophages, and determining the extent to which reprogramming of lipid metabolism in monocytes and macrophages in vivo. By applying advanced analytic techniques on tissue resident macrophages under normal, inflammatory and dyslipidemic conditions, we will determine whether activation signals and lipid environmental cues can induce or shape lipid metabolic reprogramming in vivo. We also further our understanding of how anti-inflammatory signals or ER stress signals are integrated into this process of metabolic reprogramming. Specific Aim 3 is to determine the impact of the SCD enzymes on dyslipidemia, chronic inflammation, and atherosclerosis in mice. The SCD proteins have been reported to both potentiate and attenuate atherogenesis. We suspect this is due to the complicating factor that there are multiple SCDs. In this aim, we ask if the combined loss of SCD1 and SCD2 specifically in macrophages exacerbate inflammation, dyslipidemia and atherogenesis. Conversely, can enforced SCD expression in monocytes and macrophages protect from disease. Likewise, does loss of cRel ameliorate inflammation and atheroma formation in response to western diet. It is our expectation that our proposed studies will define, at a molecular level, why dysregulation of macrophage lipid homeostasis drives inflammation, and how inflammation influences macrophage cholesterol metabolism in cardiovascular disease.