The association of SAA with apoB lipoproteins affects cardiovascular risk

描述（由申请人提供）： 心血管疾病（CVD）是发达国家发病率和死亡率的主要原因，也是退伍军人的主要健康问题。尽管有许多针对CVD风险因素的药物，但高风险个体的识别仍然不完整。此外，仍然需要鉴定用于治疗的新靶标。SAA是一种急性期反应物，在慢性炎症性疾病如糖尿病、代谢综合征（MetS）或类风湿性关节炎中显著且持续升高，这些疾病均与CVD发生率增加相关。SAA已被发现可预测CVD事件。此外，我们和其他人最近在小鼠模型中显示，SAA增加直接促动脉粥样硬化。如动脉粥样硬化对滞留的反应假说所述，血管壁蛋白聚糖对致动脉粥样硬化脂蛋白的内皮下滞留引发动脉粥样硬化。尽管在健康状态下SAA仅与HDL相关，但我们和其他人先前已报道SAA与糖尿病和/或肥胖小鼠模型中含apoB的脂蛋白相关，我们最近在人体研究中证实了这一观察结果。在初步研究中，我们证明了在胰岛素抵抗状态下SAA与含apoB的脂蛋白的关联增加，这可能是由于在胰岛素抵抗中观察到的延迟的脂蛋白清除。在新的初步研究中，我们证明SAA可以从HDL转移到含载脂蛋白B的脂蛋白。SAA本身具有蛋白聚糖结合特性，我们的初步数据表明，SAA的存在下，载脂蛋白B-脂蛋白增强其保留。这项研究的中心假设是SAA从HDL向含载脂蛋白B的脂蛋白的转变是促动脉粥样硬化的。我们认为，SAA在胰岛素抵抗条件下，如代谢综合征和糖尿病，含载脂蛋白B的脂蛋白的存在有助于增加动脉粥样硬化和心血管疾病在这些人群中观察到。使用体外，体内和临床研究，该提案的结果将确定SAA增强apoB脂蛋白的致动脉粥样硬化性，从而可以确定SAA作为治疗干预的靶点。

DESCRIPTION (provided by applicant): Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in developed nations and is a major health issue in Veterans. Despite numerous pharmacological agents targeting CVD risk factors, the identification of individuals at high risk remains incomplete. Further, there is still a need to identify new targets for therapy. SAA is an acute phase reactant that is significantly and persistently elevated in chronic inflammatory conditions such as diabetes, metabolic syndrome (MetS) or rheumatoid arthritis, which are all associated with increased rates of CVD. SAA has been found to be predictive of CVD events. Furthermore, we and others have recently shown in murine models that increased SAA is directly pro-atherogenic. As described in the Response to Retention hypothesis of atherosclerosis, the sub-endothelial retention of atherogenic lipoproteins by vascular wall proteoglycans initiates atherosclerosis. Although in the healthy state SAA is exclusively associated with HDL, we and others have previously reported SAA in association with apoB-containing lipoproteins in murine models of diabetes and/or obesity and we recently confirmed this observation in human studies. In preliminary studies we demonstrate increased association of SAA with apoB- containing lipoproteins in insulin resistant states, which may be due to the delayed lipoprotein clearance seen with insulin resistance. In new preliminary studies we demonstrate that SAA can shift from HDL to apoB-containing lipoproteins. SAA itself has proteoglycan binding properties and our preliminary data demonstrates that the presence of SAA on apoB-lipoproteins enhances their retention. The central hypothesis of this grant is that the shift of SAA from HDL to apoB-containing lipoproteins is pro-atherogenic. We propose that the presence of SAA on apoB- containing lipoproteins in insulin resistant conditions such as MetS and diabetes contributes to the increased atherosclerosis and CVD observed in these populations. Using in vitro, in vivo, and clinical studies, the results of this proposal will identify that SAA augments the atherogenicity of apoB lipoproteins and thus may identify SAA as a target for therapeutic intervention.