Suppression of AVIC inflammosteogenesis for prevention of CAVD progression

 描述(申请人提供)：钙化性主动脉瓣病(CAVD)是老年人的一种主要心血管疾病。目前，还没有药物干预来减缓或阻止这种疾病的发展。我们最近的研究发现，人主动脉瓣间质细胞(AVICs)在促炎刺激下同时表达炎症介质和成骨介质，并以碱性磷酸酶(ALP)水平升高和钙化结节形成为特征，上调促成骨活性。病变的主动脉瓣的特征显示，oxLDL在瓣膜组织中积聚，而IL-37(一种抗炎细胞因子)在AVICs中的水平降低。初步研究发现oxLDL通过TLR2和TLR4诱导AVIC表达ALP，而IL-37对AVIC促炎症反应有较强的抑制作用。重要的是，IL-37在小鼠体内的表达可以减轻高脂饮食引起的肥胖、高脂血症和主动脉瓣病变。我们为这个项目制定了两个相互关联的目标。具体目标1是检验IL-1的假设 37可抑制人血管内皮细胞的致炎反应。我们将致力于以下几个子目标：A)验证CAVD影响的AVICs中IL-37缺乏增强对危险因素的致炎反应的假说；B)确定IL37缺乏的机制；C)研究炎症介质和成骨介质在上调AVIC成骨活性中的相互作用；D)验证重组IL-37抑制病变主动脉瓣AVICs成骨活性(ALP表达/活性和钙沉积形成)的假设；E)验证IL-37抑制IRAK1从而抑制ERK1/2/NF-kB活化和人AVICs致炎反应的假说。具体目的2是确定IL-37对高脂饮食小鼠主动脉瓣病变的影响。我们的研究目标如下：1)验证TLR2/4和IRAK1在高脂饮食引起的主动脉瓣病变中起关键作用的假设；2)确定重组IL-37对高脂饮食引起的高脂血症和主动脉瓣病变的影响；3)确定IL-37的表达在高脂饮食引起的高脂血症和主动脉瓣病变中的作用。这些研究将对危险因素诱导瓣膜细胞成骨重新编程的分子机制提供深入的认识。此外，这些研究将确定抑制CAVD进展的潜在治疗靶点。

 DESCRIPTION (provided by applicant): Calcific aortic valve disease (CAVD) is a leading cardiovascular disorder in the elderly. Currently, pharmacological intervention for slowing down or halting the progression of this disease is unavailable. Our recent studies found that human aortic valve interstitial cells (AVICs) express both inflammatory and osteogenic mediators in response to pro-inflammatory stimulation and display up-regulates pro-osteogenic activity characterized by elevated levels of alkaline phosphatase (ALP) and the formation of calcification nodules. Characterization of diseased aortic valves revealed the accumulation of oxLDL in valvular tissue and reduced levels of IL-37 (an anti-inflammatory cytokine) in AVICs. Preliminary studies found that oxLDL induces AVIC expression of ALP via TLR2 and TLR4, and that IL-37 is potent in suppression of AVIC inflammosteogenic responses. Importantly, expression of IL-37 in mice attenuates obesity, hyperlipidemia and aortic valve lesions caused be high fat diet. We formulated two interrelated Aims for this project. Specific Aim 1 is to test the hypothesis that IL 37 suppresses the inflammosteogenic responses in human AVICs. We will pursue the following sub aims: A) to test the hypothesis that IL-37 deficiency in AVICs affected by CAVD augments the inflammosteogenic responses to risk factors; B) to determine the mechanism of IL-37 deficiency in AVICs of diseased human aortic valves; C) to examine the interaction of inflammatory mediators with osteogenic mediators in up-regulation of AVIC osteogenic activity; D) to test the hypothesis that recombinant IL-37 suppresses the osteogenic activity (ALP expression/activity and calcium deposit formation) in AVICs of diseased aortic valve; E) to test the hypothesis that IL-37 inhibits IRAK1 to suppress ERK1/2/NF-kB activation and the inflammosteogenic responses in human AVICs. Specific Aim 2 is to determine the effect of IL-37 on aortic valve lesions in mice fed with high fat diet. We will pursue the following sub aims: A) t test the hypothesis that TLR2/4 and IRAK1 play a critical role in mediating aortic valve lesions caused by high fat diet; B) to determine the effect of recombinant IL-37 on hyperlipidemia and aortic valve lesions caused by high fat diet; C) to determine the effect of expression of IL-37 on hyperlipidemia and aortic valve lesions caused by high fat diet. These studies will provide insights into the molecular mechanism by which risk factors induce valvular cell pro-osteogenic reprogramming. In addition, these studies will identify potential therapeutic targets for suppression of the progression of CAVD.