Anti-Atherogenic Mechanisms of Drebrin

Drebrin 的抗动脉粥样硬化机制

• 批准号: 10532356
• 负责人: NEIL J. FREEDMAN
• 金额: $ 52.33万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-16 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10532356
• 关键词: Actin-Binding Protein; Angiotensin II; Antiatherogenic; Aorta; Apolipoprotein E; Arterial Fatty Streak; Arterial Injury; Arteries; Atherosclerosis; CX3CL1 gene; Carotid Arteries; Cd68; Cell Lineage; Cell Proliferation; Cells; Cholesterol; Common carotid artery; Congestive Heart Failure; Development; Disease; Down-Regulation; Dynamin; Endocytosis; Endocytosis Inhibition; Enzymes; Exhibits; Foam Cells; Fractalkine; GKLF protein; Generations; Genes; Glutathione Metabolism Pathway; Glutathione S-Transferase; Goals; Human; In Vitro; Inflammatory; Knock-in; Knowledge; LoxP-flanked allele; Macrophage; Mass Spectrum Analysis; Mediating; Medical; Memory; Microfilaments; Mission; Molecular; Morbidity - disease rate; Mus; Myocardial Infarction; NADPH Oxidase 1; Neurons; Nuclear; Nuclear Translocation; Phagocytes; Phenotype; Prevalence; Process; Production; Proteins; Public Health; Reactive Oxygen Species; Research; Role; Signal Transduction; Smooth Muscle Myocytes; Stroke; Testing; United States National Institutes of Health; Vascular Smooth Muscle; ascending aorta; atherogenesis; burden of illness; cell motility; congenic; cytokine; disability; drebrins; in vivo; mortality; novel therapeutic intervention; oxidized low density lipoprotein; response; transcription factor; transdifferentiation; vascular inflammation; vascular injury; western diet

We discovered that the actin-binding protein, Drebrin, is abundantly expressed in smooth muscle cells (SMCs) and is up-regulated in response to arterial injury in mice and to atherosclerosis in humans. Comparing WT with Dbn-/+ mice, we found that Drebrin inhibits SMC migration and proliferation, both in vitro and in vivo, through stabilization of actin filaments. In studies with SMC-specific Dbn-/- (SMC-Dbn-/-) mice, we found that SMC Drebrin limits angiotensin II-induced remodeling of the ascending aorta, in a manner that correlates with down-regulation of NADPH oxidase 1 (NOX1), decreased SMC reactive oxygen species (ROS) production and reduced vascular inflammation. Thus, Drebrin constrains not only the migratory/proliferative SMC phenotype but also the pro-inflammatory SMC phenotype evoked by vascular injury and angiotensin II. Congruently, we found that atherosclerosis is greater in SMC-Dbn-/-/Ldlr-/- than in congenic SMC-Dbn+/+/Ldlr-/- mice. Because SMC Drebrin negatively regulates atherosclerosis, our goals are to determine the mechanisms by which Drebrin regulates SMC pro-inflammatory signaling and whether enhanced SMC expression of Drebrin can inhibit atherogenesis. To this end, we performed SILAC/mass spectrometry studies on Dbn-/- and congenic WT SMCs. We found that whereas in Dbn-/- SMCs the ROS-defensive enzyme Glutathione-S-transferase µ1 (GSTM1) is down-regulated, the pro-inflammatory cytokine CX3CL1 (fractalkine) is up-regulated: thus we will investigate the role of these proteins in mediating the phenotype of Dbn-/- SMCs. Because endocytosis of NOX1 regulates ROS generation and activation of pro-inflammatory NFκB signaling and Drebrin has been shown to inhibit endocytosis, we will investigate whether Drebrin inhibits NOX1-mediated ROS generation by inhibiting endocytosis. A major focus of our studies will be pro-atherogenic SMC-derived foam cells, which SMC lineage tracing studies have shown, comprise ~40% of foam cells in atherosclerotic lesions. Our Preliminary Studies show that, compared with cognate Dbnflox/flox SMCs, Dbn-/- SMCs induced to transdifferentiate with cholesterol loading exhibited increased expression of the macrophage marker, CD68, and Kruppel-like factor 4 (KLF4), a transcription factor required for SMC-to-foam cell transdifferentiation. By grafting common carotid arteries from Dbnflox/flox and SMC-Dbn-/- mice into carotid arteries of congenic Apoe-/- mice, we also show that Drebrin deficiency augments transdifferentiation of SMCs to CD68+ cells in vivo. We will test the hypothesis that Drebrin inhibits atherogenesis by limiting SMC transdifferentiation into foam cells. To do so, we will establish whether Drebrin inhibits SMC-to-foam cell transdifferentiation and associated pro- inflammatory signaling, both in vitro and in vivo; determine if Drebrin inhibits SMC transdifferentiation through ROS-dependent mechanisms; and define the roles of GSTM1 and CX3CL1 in mediating Drebrin’s inhibitory effects on SMC transdifferentiation and pro-inflammatory signaling.

我们发现肌动蛋白结合蛋白Drebrin在平滑肌细胞（SMC）中绝对表达 并因小鼠的动脉损伤和人类动脉粥样硬化而被上调。比较wt 使用DBN-/+小鼠，我们发现Drebrin在体外和体内都抑制SMC迁移和增殖， 通过稳定肌动蛋白丝。在SMC特异性DBN - / - （SMC-DBN - / - ）小鼠的研究中，我们发现 SMC DREBRIN限制了血管紧张素II诱导的升主动脉的重塑，以与 NADPH氧化物1（NOX1）的下调，精制的SMC活性氧（ROS）产生和 血管炎症减少。这，德雷布林不仅限制了迁移/增殖的SMC表型 还有血管损伤和血管紧张素II引起的促炎SMC表型。一致，我们 发现在SMC-DBN - / - /LDLR - / - 中，动脉粥样硬化要大于先天性SMC-DBN+/+/ldlr - / - 小鼠。因为 SMC DREBRIN负面调节动脉粥样硬化，我们的目标是确定其机制 Drebrin调节SMC促炎信号传导以及Drebrin的SMC表达是否可以 抑制动脉粥样硬化。为此，我们对DBN - / - 进行了SILAC/质谱研究 WT SMC。我们发现，虽然在DBN - / - SMC中，ROS防御性谷胱甘肽-S-转移酶µ1 （GSTM1）被下调，促炎性细胞因子CX3CL1（fractalkine）被上调：因此，我们将 研究这些蛋白质在介导DBN - / - SMC的表型中的作用。因为内吞作用 NOX1调节ROS的产生和促炎性NFκB信号传导和DREBRIN的激活已是 证明可以抑制内吞作用，我们将研究Drebrin是否通过 抑制内吞作用。我们研究的主要重点是促动脉粥样硬化的SMC衍生的泡沫细胞，该细胞 SMC谱系追踪研究表明，在动脉粥样硬化病变中占ibe虫细胞的约40％。我们的 初步研究表明，与dbnflox/flox SMC相比，DBN - / - SMC诱导的 胆固醇载荷暴露于巨噬细胞标记CD68， 和类似Kruppel的因子4（KLF4），这是SMC到泡沫细胞转分化所需的转录因子。经过 将dbnflox/flox和smc-dbn - / - 小鼠从颈动脉接枝的颈动脉 - / - 小鼠，我们还表明，德雷布林缺乏症会增加体内SMC对CD68+细胞的转变。我们 将测试DREBRIN通过将SMC转分解为泡沫细胞抑制动脉粥样硬化的假设。 为此，我们将确定DREBRIN是否抑制SMC到泡沫细胞的转变和相关的促剂 体外和体内炎症信号传导；确定Drebrin是否通过 ROS依赖机制；并定义GSTM1和CX3CL1在介导Drebrin的抑制作用中的作用 对SMC转分解和促炎信号传导的影响。

项目成果

Drebrin attenuates atherosclerosis by limiting smooth muscle cell transdifferentiation.

• DOI: 10.1093/cvr/cvab156
• 发表时间: 2021-04
• 期刊: Cardiovascular research
• 影响因子: 10.8
• 作者: Jiao‐Hui Wu;Lisheng Zhang;Igor Nepliouev;L. Brian;Taiqin Huang;Kamie P Snow;B. Schickling;E. Hauser;F. Miller;N. Freedman;Jonathan A Stiber