Innate Immune Activation and Endothelial Cell Dysfunction in Acute Kawasaki Disease

超过25%的儿童患有川崎（KD），这是儿科获得性心脏病的最常见原因 疾病，发展冠状动脉异常（CAAs），尽管标准治疗与静脉 免疫球蛋白。动脉瘤一旦形成，对动脉壁的损伤是不可逆的，如狭窄 和钙化，可能导致缺血性并发症。这个合作团队已经建立了激活机制， IL-1通路和内皮-间充质转化（EndoMT），下调krüppel样 因子4（KLF 4）是KD血管炎发病机制的关键。我们新发现的TIFA（TNF）的中心作用， 具有叉头相关结构域的受体相关因子相互作用蛋白 内皮细胞（EC）损伤中的活化被认为是KD血管炎的进一步机制。我们提出一个大胆的 我计划将这个研究团队与血管生物学、免疫学和临床KD的专业知识结合起来， KD血管损伤的潜在机制，并引导一种新的治疗方法。指导性假设 急性KD不仅激活了内皮细胞中的IL-1/TIFA/NLRP 3炎性体，而且还降低了EC 内稳态，这两者在KD的发病机制中都是关键的。IL-1依赖性先天性 阿那白滞素（重组IL-1 R拮抗剂）联合EC功能恢复的免疫应答 阿托伐他汀可减轻急性KD的血管损伤。提出了三个具体目标来检验这一假设。 特异性目标1将阐明阿那白滞素阻断先天性免疫激活的分子基础， 与KD血管炎相关的反应。体外、离体和体内实验将研究IL-1的作用， TIFA和NLRP 3在KD介导的EC功能障碍和血管炎中的作用， 重组过表达，药理学激动剂和抑制剂（包括阿那白滞素），以及缺失- 功能小鼠具体目标2将阐明阿托伐他汀恢复EC功能的分子基础， 急性川崎病KLF 4功能获得和丧失的小鼠品系以及谱系追踪实验将在 进行解密KD血管病变EC功能障碍的分子机制。具体目标 3将确定阿那白滞素/阿托伐他汀联合治疗在注射LCWE的小鼠中的协同作用， 在KD患者中。LCWE小鼠模型，包括Tifa-/-和Klf 4-/-，将用于测试以下的作用： 阿那白滞素/阿托伐他汀联合治疗对血管炎症和EC功能的影响。此外，急性KD 患有早期CAA的患者将参加阿那白滞素/阿托伐他汀联合治疗的初步研究。细胞因子 将在治疗前和治疗后测量血清中的MMP水平和MMP活性以及全血RNA中的转录物丰度。 治疗这些血清也将在体外用培养的EC进行检测，并读出EC先天免疫 反应和EC功能障碍。本多PI提案中三个团队的协同专业知识提供了 独特的机会，了解KD血管病变的分子机制，并迅速翻译 将研究结果转化为在儿童中进行的体外和体内治疗效果评估的初步研究。

More than 25% of children with Kawasaki disease (KD), the most common cause of pediatric acquired heart disease, develop coronary artery abnormalities (CAAs) despite standard therapy with intravenous immunoglobulin. Once aneurysms have formed, the damage to the arterial wall is irreversible, such as stenoses and calcification that may lead to ischemic complications. This collaborative team has established that activation of the IL-1 pathway and endothelial-to-mesenchymal transition (EndoMT) with downregulation of krüppel-like factor 4 (KLF4) are key to the pathogenesis of KD vasculitis. Our novel discovery of the central role of TIFA (TNF receptor-associated factor-interacting protein with a forkhead-associated domain) in NLRP3 inflammasome activation in endothelial cell (EC) injury is proposed as a further mechanism of KD vasculitis. We propose a bold plan to unite this research team with expertise in vascular biology, immunology, and clinical KD to unravel the mechanisms underlying vascular injury in KD and pilot a novel therapeutic approach. The guiding hypothesis is that acute KD not only activates the IL-1/TIFA/NLRP3 inflammasome in the endothelium, but also reduces EC homeostasis, both of which are critical in the pathogenesis of KD. The blockade of the IL-1-dependent innate immune response by anakinra (recombinant IL-1R antagonist) in combination with the restoration of EC function by atorvastatin will reduce vascular damage in acute KD. Three specific aims are proposed to test this hypothesis. Specific Aim 1 will delineate the molecular basis by which anakinra blocks activation of the innate immune response associated with KD vasculitis. In vitro, ex vivo, and in vivo experiments will investigate the role of IL-1, TIFA, and NLRP3 in KD-mediated EC dysfunction and vasculitis using pathway-specific siRNA knockdown, recombinant overexpression, pharmacologic agonists and inhibitors (including anakinra), as well as loss-of- function mice. Specific Aim 2 will elucidate the molecular basis by which atorvastatin restores EC function in acute KD. Mouse lines with gain- and loss-of-function of KLF4 as well as lineage tracing experiments will be performed to decipher the molecular mechanisms underlying EC dysfunction in KD vasculopathy. Specific Aim 3 will determine the synergistic effect of anakinra/atorvastatin combination therapy in LCWE-injected mice and in KD patients. LCWE mouse models, including Tifa-/- and Klf4-/-, will be utilized to test the effect of anakinra/atorvastatin combination therapy on vascular inflammation and EC function. Furthermore, acute KD patients with early CAAs will be enrolled in a pilot study of anakinra/atorvastatin combination therapy. Cytokine levels and MMP activity in sera and transcript abundance in whole blood RNA will be measured pre- and post- treatment. These sera will also be tested in vitro with cultured ECs with read-outs for EC innate immune responses and EC dysfunction. The synergistic expertise of the three teams in this multi-PI proposal provides a unique opportunity to understand molecular mechanisms underlying KD vasculopathy and rapidly translate the findings into a pilot study in children with in vitro and in vivo assessments of the treatment effect.