Supplementary Material for: Recombinant Human Soluble Thrombomodulin Suppresses Arteritis in a Mouse Model of Kawasaki Disease

<b><i>Introduction and Objective:</i></b> Kawasaki disease (KD) is associated with diffuse and systemic vasculitis of unknown aetiology and primarily affects infants and children. Intravenous immunoglobulin (IVIG) treatment reduces the risk of developing coronary aneurysms, but some children have IVIG-resistant KD, which increases their risk of developing coronary artery injury. Here, we investigated the effect of recombinant human soluble thrombomodulin (rTM), which has anticoagulant, anti-inflammatory, and cytoprotective properties on the development of coronary arteritis in a mouse model of vasculitis. <b><i>Methods:</i></b> An animal model of KD-like vasculitis was created by injecting mice with <i>Candida albicans</i> water-soluble fraction (CAWS). This model was used to investigate the mRNA expression of interleukin (IL)-10, tumour necrosis factor alpha (TNF-α), and tissue factor (TF), in addition to histopathology of heart tissues. <b><i>Results:</i></b> rTM treatment significantly reduces cardiac vascular endothelium hypertrophy by 34 days after CAWS treatment. In addition, mRNA expression analysis revealed that rTM administration increased cardiac IL-10 expression until day 27, whereas expression of TNF-α was unaffected. Moreover, in the spleen, rTM treatment restores IL-10 and TF expression to normal levels. <b><i>Conclusion:</i></b> These findings suggest that rTM suppresses CAWS-induced vasculitis by upregulating IL-10. Therefore, rTM may be an effective treatment for KD.

<b><i>研究背景与目的：</i></b> 川崎病（Kawasaki disease, KD）是一种病因未明的弥漫性系统性血管炎，主要累及婴幼儿群体。静脉注射免疫球蛋白（intravenous immunoglobulin, IVIG）可降低冠状动脉瘤的发生风险，但部分患儿会出现IVIG耐药型川崎病，这会进一步提升其冠状动脉损伤的风险。本研究旨在探究具有抗凝、抗炎及细胞保护特性的重组人可溶性血栓调节蛋白（recombinant human soluble thrombomodulin, rTM）对血管炎小鼠模型中冠状动脉炎发生发展的影响。
<b><i>研究方法：</i></b> 本研究通过向小鼠注射白色念珠菌水溶性组分（Candida albicans water-soluble fraction, CAWS）构建类川崎病血管炎动物模型。利用该模型，我们检测了心脏组织的病理组织学变化，并分析了白细胞介素-10（interleukin-10, IL-10）、肿瘤坏死因子-α（tumour necrosis factor alpha, TNF-α）以及组织因子（tissue factor, TF）的mRNA表达水平。
<b><i>研究结果：</i></b> rTM治疗可在CAWS造模后第34天显著减轻心脏血管内皮肥大。mRNA表达分析显示，rTM给药可在造模后第27天提升心脏组织中IL-10的表达水平，而对TNF-α的表达无显著影响。此外，rTM治疗可使脾脏中IL-10和TF的表达恢复至正常水平。
<b><i>研究结论：</i></b> 上述研究结果表明，rTM可通过上调IL-10的表达抑制CAWS诱导的血管炎。因此，rTM或可成为治疗川崎病的有效手段。