Suppression of AVIC inflammosteogenesis for prevention of CAVD progression

 描述（由申请人提供）：钙化性主动脉瓣疾病（CAVD）是老年人的主要心血管疾病。目前，还没有减缓或阻止这种疾病进展的药物干预。我们最近的研究发现，人主动脉瓣间质细胞（AVIC）表达炎症和成骨介质，以响应促炎刺激，并显示上调促成骨活性，其特征是碱性磷酸酶（ALP）水平升高和钙化结节的形成。病变主动脉瓣的表征揭示了oxLDL在瓣膜组织中的积累和AVIC中IL-37（一种抗炎细胞因子）水平的降低。初步研究发现，oxLDL通过TLR 2和TLR 4诱导AVIC表达ALP，并且IL-37有效抑制AVIC炎性成骨反应。重要的是，小鼠中IL-37的表达减轻了由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 37抑制人AVIC中的炎性成骨反应。本研究的主要目的是：（1）验证CAVD患者AVIC中IL-37缺乏增强了对危险因素的炎性成骨反应的假说;（B）确定IL-37缺乏在患病人主动脉瓣AVIC中的机制;（3）检测炎性介质与成骨介质在AVIC成骨活性上调中的相互作用; D）检验重组IL-37抑制患病主动脉瓣的AVIC中的成骨活性（ALP表达/活性和钙存款形成）的假设; E）检验IL-37抑制IRAK 1以抑制人AVIC中的ERK 1/2/NF-kB活化和炎性成骨反应的假设。具体目的2是确定IL-37对高脂饮食喂养的小鼠中的主动脉瓣病变的影响。我们将追求以下子目标：A）t检验TLR 2/4和IRAK 1在介导高脂饮食引起的主动脉瓣病变中发挥关键作用的假设; B）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; C）确定IL-37的表达对高脂饮食引起的高脂血症和主动脉瓣病变的影响。这些研究将为风险因素诱导瓣膜细胞促成骨重编程的分子机制提供见解。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.