川崎病血管内皮细胞损伤的新机制-内皮微颗粒中miR-199b-5p的作用

Kawasaki disease (KD) which is characterized by immunological vasculitis is one of the high risk factors of coronary heart disease. Elevated concentrations of EMPs have been associated with Kawaski diseases recently, but the mechanism of how EMPs result in endothelial cells injury remains unclear. We found in prophase study that : EMPs derived from peripheral blood of KD patients are rich in miR-199b-5p. Synthetic precursor of miR-199b-5p can result in endothelial cell lesions，which is the same as EMPs; Bioinformatics predicts that IkB is a target gene of miR-199b-5p, and the interrelation between NF-kB/IkB signal pathway and endothelial cell lesions in patients with KD has been confirmed, so we hypothesize a new mechanism that miR-199b-5p initiating the IkB signal pathway results in endothelial cells injury in patients with KD. The study design of the new mechanism is as follows: ① To study the correlation between miR-199b-5p in EMP and the endothelial cell lesions in patients with KD,and in animal models and cell models; ②To observe the influence of expressed IkB when miR-199b-5p overexpressed or silent expressed in endothelial cells , in order to analyze the mechanism that miR-199b-5p results in endothelial cell lesions by regulating the expression of IkB; ③ To verify the hypothesis that miR-199b-5p can result in endothelial cell lesions in normal rabbits and vitro endothelial cells model.This mechanism hypothesis, which has not been reported up to now, is a kind of original design that can provide new clues and potential therapeutic targets for KD.

以免疫性血管炎为特征的川崎病(Kawasaki Disease KD)是冠心病的高危因素。最近报道KD的内皮微颗粒（Endothelial Microparticle EMP）明显增加，其作用机制未明。我们前期研究发现：KD患儿EMP富含miR-199b-5p；合成的miR-199b-5p前体与EMP一样损伤血管内皮细胞；生物信息学预测miR-199b-5p的靶基因是IkB。而公认NF-kB/IkB调控KD血管损伤。因此我们设想:EMP中miR-199b-5p调控IkB是导致KD血管内皮损伤的新机制。本研究拟探讨：①KD患儿和兔模型血EMP中miR-199b-5p水平与血管内皮损伤和IkB表达相关性；②其过表达/表达沉默对血管内皮细胞生长和IkB的影响；③其损伤正常血管内皮的体内外研究；以验证其通过调控IkB而损伤血管内皮，该机制尚未见报道，具有源头创新性，为KD防治提供新线索和干预靶标。

川崎病后血管内皮功能持续性障碍，如何从源头上减轻血管内皮细胞损伤以改善川崎病预后是迫切需要解决的临床实际问题。本项目旨在通过体内外实验，阐明 miR-199b-5p 通过调控其下游靶基因，及相关的分子机制，参与川崎病血管内皮炎症损伤，为川崎病的早期诊断及干预治疗提供新的理论依据和潜在的干预靶标。.①在临床实验中，我们研究了 miR-199b-5p 在 KD 不同临床分期、不同冠状动脉损伤程度临床病例与 NF-κB/IκB 相关性，发现在川崎病急性期，血浆中 miR-199b-5p 的相对表达量和单个核细胞中 NF-κB/IκB 较对照组明显升高。② miR-199-5p 在冠状动脉损害鼠模型冠状动脉组织中与 NF-κB/IκB 相关性研究，发现 miR-199b-5p的变化与冠状动脉组织中的炎症因子 TNF-α、IL-6 水平及冠状动脉损害呈正相关。 ③细胞实验完成了不同刺激物、不同刺激时间刺激脐静脉内皮细胞后 miR-199b-5p 表达量研究，发现在高浓度 LPS 或 TNF- a 刺激的内皮细胞中 miR-199-5p 的表达量明显升高。以上研究说明 miR-199b-5p 在 KD 血管内皮损伤中期重要作用。