Phosphatidylinositol Metabolism and Trafficking in Atherosclerosis and Inflammation

项目摘要 PIP 2是一种次要磷脂（PL），在多种细胞功能中起关键作用， PIP 2在动脉粥样硬化和Nlrp 3/ IL-1介导炎性体通路中作用尚不清楚 表征了我以前已经证明ABCA 1作为磷脂酰肌醇4，5- 二磷酸（PIP 2）翻转酶，将PIP 2从血浆的内小叶转运到外小叶 膜的ABCA 1是一种细胞胆固醇外排转运蛋白，在预防高胆固醇血症中起着重要作用。 动脉粥样硬化和炎症通过从细胞流出过量的脂质/胆固醇和通过 阻断促炎通路具有Abca 1突变的人类患者患有 Ldlr基因敲除小鼠早期动脉粥样硬化及ABCA 1/G1基因敲除 促进动脉粥样硬化和斑块炎症。促炎性Nlrp 3/IL-1的作用 CANTOS试验强调了动脉粥样硬化中的IL-1 β通路，表明抗IL-1β治疗 达到了主要试验终点，即心脏病发作、中风和 心血管死亡最近的研究表明，Gasdermin D（GsdmD），一种新的 发现了炎性小体的底物，与质膜上的PIP 2结合， 寡聚化，产生用于释放成熟IL-1 β的孔。拟议中的研究将揭开 PIP 2在这些通路中的新作用，可能为治疗干预打开新的窗口 预防心血管疾病（CVD）。这一建议将进一步确立PIP 2作为一个主要的 细胞胆固醇流出调节因子并鉴定PIP 2翻转酶（P4型ATP酶， 将PIP 2从质膜的外部小叶运输到内部小叶），其又调节 胆固醇流出和炎症。该提案将确定全球可持续发展司的作用， 动脉粥样硬化，逆转胆固醇转运（RCT），以及逆转 RCT中的炎症。该提案的三个主要目标是：1）将PIP 2建立为 主要的细胞胆固醇流出调节剂，2）鉴定和表征PIP 2翻转酶， 确定P4型ATP酶在胆固醇流出和炎症中的作用，以及3） 确定Gasdermin D在动脉粥样硬化和RCT中的作用。

Project Summary PIP2 is a minor phospholipid (PL) and plays a critical role in a variety of cellular functions but the role of PIP2 in atherosclerosis and Nlrp3/ IL-1 inflammasome pathway is not well characterized. I have previously shown that ABCA1 functions as a phosphatidylinositol 4, 5- bisphosphate (PIP2) floppase, transporting PIP2 from the inner to the outer leaflet of the plasma membrane. ABCA1, a cellular cholesterol efflux transporter, plays a major role in preventing atherosclerosis and inflammation by effluxing excess lipids/cholesterol from cells and by blocking pro-inflammatory pathways. Human patients with mutations in Abca1 suffer from premature atherosclerosis and macrophage-specific knockout of ABCA1/G1 in Ldlr KO mice promotes atherosclerosis and plaque inflammation. The role of pro-inflammatory Nlrp3/IL- 1pathway in atherosclerosis was highlighted by CANTOS trial showing that anti-IL-1β therapy met the primary trial endpoint, a reduction in a composite of heart attack, stroke and cardiovascular death. Recent studies have shown that Gasdermin D (GsdmD), a newly discovered substrate of the inflammasome, binds to PIP2 on the plasma membrane and oligomerize, generating pores for releasing mature IL-1. The proposed studies will unravel the novel roles of PIP2 in these pathways and may open new windows for therapeutic intervention to prevent cardiovascular disease (CVD). This proposal will further establish PIP2 as a major regulator of cellular cholesterol efflux and identify the PIP2 flippases (P4-type ATPases that transport PIP2 from the outer to the inner leaflet of the plasma membrane) that in turn regulate cholesterol efflux and inflammation. The proposal will identify the role of GsdmD in atherosclerosis, reverse cholesterol transport (RCT), and in reversing the negative effects of inflammation on RCT. The three main goals of this proposal are; 1) to establish PIP2 as a major cellular cholesterol efflux regulator, 2) to identify and characterize the PIP2 flippase and determine the role of P4-type ATPases in cholesterol efflux and inflammation, and 3) to determine the role of Gasdermin D in atherosclerosis and RCT.