Pro-inflammatory S100 protein as disease modifier in calcific aortic valve diseas

描述(由申请人提供)： 钙化性主动脉瓣疾病在老龄化人口中是一个日益严重的健康问题。为了克服我们对疾病过程的有限了解，并开发出瓣膜置换以外的治疗策略，迫切需要更好的动物模型。到目前为止，大多数动物模型都集中在高脂血症引起的血管炎症上。我们的研究实验室专注于细胞因子样蛋白S100A12，这在小鼠中不存在。S100A12在小鼠中的缺失可能是正常血脂小鼠血管炎症总量减少的原因之一。我们现在利用人S100基因簇及其内源调控元件，在正常表达这些蛋白的组织中开发了一种新的人源化转基因小鼠，在这些组织中表达人S100/钙颗粒蛋白(S100A12、S100A8和S100A9)。这些小鼠被命名为hBAC-S100，因为这种模型是使用细菌人工染色体来产生的。这些小鼠有一个“促炎”的环境，并以脂质中性的方式发展为伴有微钙化的主动脉瓣疾病。在目的1中，我们想要检测转基因hBAC-S100小鼠的全身和局部炎症状态，并研究S100/钙粒蛋白诱导主动脉瓣钙化的机制。在AIM 2中，我们希望使用人源化的S100/钙粒蛋白小鼠，通过将这些小鼠暴露于额外的血管应激源，如高脂血症和慢性肾脏疾病，来开发晚期钙化性主动脉瓣疾病的新模型。我们的假设是，人类S100A12是一种疾病改善因子，通过其对应激细胞的促凋亡作用，加速代谢挑战小鼠的钙化性主动脉瓣疾病。在我们之前的工作中，我们在转基因小鼠中证明了动脉粥样硬化和血管钙化的极大加速，转基因小鼠的血管平滑肌靶向人S100A12的表达，并暴露于高脂血症或慢性肾脏疾病。在AIM 3中，我们想要验证这样一种假设，即通过阻止S100/钙粒蛋白受体RAGE的激活或通过损害S100/RAGE轴的下游信号来限制S100/Calgrain诱导的慢性炎症将减缓体内钙化性主动脉瓣疾病的进展。我们的研究将有助于更好地了解全身和局部主动脉瓣炎症的关系。通过阐明S100/钙颗粒蛋白调节其对主动脉瓣重塑的影响的机制，将确定哪些步骤应作为治疗的靶点。我们的实验将确定S100/钙颗粒蛋白/RAGE轴是否是治疗主动脉瓣疾病的足够靶点。 (摘要结束)

DESCRIPTION (provided by applicant): Calcific aortic valve disease is a growing health problem in our aging population. To overcome our limited understanding in the disease process and to develop therapeutic strategies beyond valve replacement, better animal models are critically needed. To date, most animal models have focused on hyperlipidemia-induced vascular inflammation. Our research laboratory focuses on the cytokine-like protein S100A12, which is not present in mice. The absence of S100A12 in mice could be one reason for an overall reduced amount of vascular inflammation seen in normolipidemic mice. We now developed a new humanized transgenic mouse with expression of human S100/calgranulins (S100A12, S100A8 and S100A9) in tissues that normally express these proteins by using the human S100 gene cluster with its endogenous regulatory elements. These mice are termed hBAC-S100 since a bacterial artificial chromosome was used to generate this model. These mice have a "pro-inflammatory" milieu and develop aortic valve disease with micro-calcification in a lipid neutral manner. In AIM 1 we would like to examine systemic and local inflammatory state in transgenic hBAC-S100 mice and study mechanisms by which S100/Calgranulins induce calcification of the aortic valve. In AIM 2 we would like to use the humanized S100/calgranulin mouse to develop new models of advanced calcific aortic valve disease by exposing these mice to additional vascular stressors, like hyperlipidemia and chronic kidney disease. It is our hypothesis that human S100A12 is a disease-modifying factor that accelerates calcific aortic valve disease in metabolically challenged mice by its pro-apoptotic effects on stressed cells. In our previous work we demonstrated vastly accelerated atherosclerosis and vascular calcification in transgenic mice with expression of human S100A12 targeted to the vascular smooth muscle and exposed to hyperlipidemia or chronic kidney disease. In AIM 3 we would like to test the hypothesis that limiting S100/calgranulin induced chronic inflammation by either preventing activation of its receptor RAGE or by impaired downstream signaling of the S100/RAGE axis will attenuate the progression of calcific aortic valve disease in vivo. Our research will contribute to a better understanding of the relationship of systemic and local aortic valve inflammation. Delineating the mechanisms by which S100/calgranulin regulates its effect on aortic valve remodeling will identify those steps that should be targeted for therapy. Our experiments will identify whether the S100/calgranulins/RAGE axis is a sufficient therapeutic target for aortic valve disease. (End of Abstract)