Histone deacetylases and atherosclerosis

描述(申请人提供)：尽管降脂药物在预防冠状动脉疾病和心肌梗死方面取得了成功，但动脉粥样硬化仍然是西方世界和发展中国家与疾病相关的死亡的最常见原因。我们和其他人已经证明了组蛋白脱乙酰酶抑制剂(HDI)具有抗炎作用，并可用于治疗某些慢性炎症性疾病。鉴于动脉粥样硬化的炎性成分，根据我们的初步数据，本研究中要检验的假设是，组蛋白脱乙酰酶9(HDAC9)通过调节巨噬细胞中脂质稳态和炎症基因的表达，在动脉粥样硬化的发病机制中发挥重要作用。我们的长期目标是开发用于治疗和预防动脉粥样硬化的选择性HDIs。提出了三个具体目标。特定目的1将测试假设，即巨噬细胞中HDAC9的失活将减少，过度表达将通过改变体内脂质稳态和炎症基因而增加LDLR-/-小鼠的动脉粥样硬化。我们将从HDAC9基因缺陷小鼠和HDAC9转基因小鼠进行骨髓移植到LDLR-/-小鼠，并检测其对动脉粥样硬化的影响。具体目标2将验证HDAC9通过调节巨噬细胞内胆固醇外流和内流途径来调节脂质稳态的假设。我们将使用硫代葡萄糖酸盐诱导的腹膜巨噬细胞或骨髓来源的巨噬细胞来研究不同水平的HDAC9表达对胆固醇流出(ABCA1、Abcg1和SR-B1介导)、胆固醇酯化以及脂蛋白结合和降解的影响。具体目标3将检验HDAC9活性调节巨噬细胞炎症的假设。我们将使用表达不同数量HDAC9的巨噬细胞进行跨内皮细胞迁移、趋化和黏附试验。荧光或放射性标记的巨噬细胞将被用来监测单核-巨噬细胞在体内对动脉粥样硬化斑块的归巢。我们还将检测在IPS刺激下表达不同数量HDAC9的巨噬细胞中的细胞因子、趋化因子、整合素和黏附分子。这项研究将为HDAC9在动脉粥样硬化发病机制中的作用提供新的见解。最终，这项研究可能为开发仅针对HDAC9治疗人类动脉粥样硬化的特异组蛋白去乙酰化酶抑制剂提供基础。

DESCRIPTION (provided by applicant): Despite the success of lipid lowering drugs for the prevention of coronary artery disease and myocardial infarction, atherosclerosis remains the most common cause of disease-related death in the Western world and in developing countries. We and others have demonstrated that histone deacetylase inhibitors (HDIs) have anti-inflammatory effects and can be used to treat certain chronic inflammatory diseases. Given the inflammatory component of atherosclerosis, and based on our preliminary data, the hypothesis to be tested in this proposal is that histone deacetylase 9 (HDAC9) plays an important role in the pathogenesis of atherosclerosis by regulating the expression of lipid homeostatic and inflammatory genes in macrophages. Our long term goal is to develop selective HDIs for the treatment and prevention of atherosclerosis. Three specific aims are proposed. Specific Aim 1 will test the hypothesis that inactivation of HDAC9 in macrophages will decrease, and overexpression will increase atherosclerosis in Ldlr -/- mice by modifying lipid homeostatic and inflammatory genes in vivo. We will do bone marrow transplant from HDAC9 deficient and HDAC9 transgenic mice to Ldlr-/- mice and determine its effect on atherosclerosis. The Specific Aim 2 will test the hypothesis that HDAC9 mediates lipid homeostasis by modulating cholesterol efflux and influx pathways in macrophages. We will use thioglyocollate-elicited peritoneal macrophages or bone marrow derived macrophages to study the effect of different levels of expression of HDAC9 on cholesterol efflux (ABCA1, ABCG1, and SR-B1 mediated), cholesterol esterification, and lipoprotein binding and degradation. Specific Aim 3 will test the hypothesis that HDAC9 activity regulates inflammation in macrophages. We will perform transendothelial migration, chemotaxis, and adhesion assays using macrophages expressing different amounts of HDAC9. Fluorescent or radiolabeled macrophages will be used to monitor monocyte- macrophage homing to atherosclerotic plaques in vivo. We will also measure cytokine, chemokines, integrins and adhesion molecules in macrophages expressing different amount of HDAC9 upon IPS stimulation. This study will provide new insight into the mechanisms by which HDAC9 plays a role in the pathogenesis of atherosclerosis. Ultimately, this study may provide the foundation for the development of specific histone deacetylase inhibitors that only targets HDAC9 for the treatment of atherosclerosis in humans.