CHI3L1在川崎病样血管炎小鼠模型冠状动脉损伤中的作用及机制研究

Role and mechanisms of CHI3L1 in coronary artery lesions in a mouse model of Kawasaki disease-like vasculitis

摘要:

目的 探究壳多糖酶3样蛋白1（chitinase-3-like protein 1, CHI3L1）在川崎病（Kawasaki disease, KD）样血管炎小鼠模型冠状动脉损伤中的作用及其潜在机制。方法 将4周龄雄性SPF级C57BL/6小鼠随机分为正常对照组和模型组，每组10只。模型组小鼠通过腹腔注射干酪乳杆菌细胞壁提取物（lactobacillus casei cell wall extract, LCWE）0.5 mL构建KD样血管炎小鼠模型，对照组腹腔注射等量的生理盐水。注射后第3天、第7天和第14天观察小鼠的一般情况。采用苏木精-伊红染色法观察冠状动脉组织病理学变化。采用酶联免疫吸附法检测小鼠血清中CHI3L1水平。采用免疫荧光染色法检测CHI3L1、血管性血友病因子（von Willebrand factor, vWF）、α-平滑肌肌动蛋白（α-smooth muscle actin, α-SMA）在冠状动脉组织中的表达及定位。采用Western blot法检测冠状动脉组织中CHI3L1、vWF、血管内皮钙黏蛋白（vascular endothelial cadherin, VE cadherin）、半胱天冬酶-3（Caspase-3）、B细胞淋巴瘤-2（B cell lymphoma-2, Bcl-2）、Bcl-2相关X蛋白（Bcl-2 associated X protein, Bax）、核转录因子κB（nuclear factor-κB, NF-κB）及磷酸化NF-κB（p-NF-κB）表达情况。结果 模型组小鼠血清中CHI3L1含量较对照组明显升高（P<0.05）。与对照组相比，模型组小鼠冠状动脉组织中CHI3L1表达高于对照组，vWF表达低于对照组。模型组小鼠CHI3L1、Bax、Caspase-3、NF-κB及p-NF-κB蛋白相对表达量明显高于对照组（P<0.05）。模型组vWF、VE cadherin和Bcl-2蛋白相对表达量低于对照组（P<0.05）。结论 LCWE诱导的KD样血管炎小鼠模型中，血清及冠状动脉CHI3L1的表达水平升高，可能通过炎性反应介导血管内皮细胞凋亡在冠状动脉损伤中发挥作用。

Abstract:

Objective To explore the role and potential mechanisms of chitinase-3-like protein 1 (CHI3L1) in coronary artery lesions in a mouse model of Kawasaki disease (KD)-like vasculitis.Methods Four-week-old male SPF-grade C57BL/6 mice were randomly divided into a control group and a model group, with 10 mice in each group. The model group mice were intraperitoneally injected with 0.5 mL of lactobacillus casei cell wall extract (LCWE) to establish a mouse model of KD-like vasculitis, while the control group mice were injected with an equal volume of normal saline. The general conditions of the mice were observed on the 3rd, 7th, and 14th day after injection. Changes in coronary artery tissue pathology were observed using hematoxylin-eosin staining. The level of CHI3L1 in mouse serum was measured by enzyme-linked immunosorbent assay. Immunofluorescence staining was used to detect the expression and localization of CHI3L1, von Willebrand factor (vWF), and α-smooth muscle actin (α-SMA) in coronary artery tissue. Western blot analysis was used to detect the expression of CHI3L1, vWF, vascular endothelial cadherin (VE cadherin), Caspase-3, B cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), nuclear factor κB (NF-κB), and phosphorylated NF-κB (p-NF-κB) in coronary artery tissue.Results The serum level of CHI3L1 in the model group was significantly higher than that in the control group (P<0.05). Compared to the control group, the expression of CHI3L1 in the coronary artery tissue was higher, while the expression of vWF was lower in the model group. The relative expression levels of CHI3L1, Bax, Caspase-3, NF-κB, and p-NF-κB were significantly higher in the model group than in the control group (P<0.05). The relative expression levels of vWF, VE cadherin, and Bcl-2 were lower in the model group than in the control group (P<0.05).Conclusions In the LCWE-induced mouse model of KD-like vasculitis, the expression levels of CHI3L1 in serum and coronary arteries increase, and it may play a role in coronary artery lesions through endothelial cell apoptosis mediated by inflammatory reactions.