骨髓间充质干细胞分泌半乳凝素1可抑制哮喘小鼠的气道炎症

Galectin-1 secreted by bone marrow mesenchymal stem cells may suppress airway inflammation in an asthmatic mouse

背景:课题组前期研究表明移植骨髓间充质干细胞能减轻哮喘气道炎症程度且能调节哮喘炎症因子水平,进一步体外研究提示骨髓间充质干细胞分泌的半乳凝素1能影响树突状细胞的免疫功能,而骨髓间充质干细胞分泌的半乳凝素1对哮喘的作用尚不明确。目的:观察骨髓间充质干细胞分泌的半乳凝素1对哮喘小鼠气道炎症的影响。方法:构建小鼠pLVX-gal-1-shRNA并感染骨髓间充质干细胞。取40只雌性BALB/c小鼠,随机分为正常对照组、哮喘模型组、骨髓间充质干细胞组、重组半乳凝素1蛋白组、干扰半乳凝素1表达的骨髓间充质干细胞组,对比各组小鼠肺泡灌洗液中炎症细胞总数及分类的差异,采用苏木精-伊红染色观察各组小鼠气道炎症变化。结果与结论:(1)针对小鼠半乳凝素1基因设计了4条RNA干扰序列,通过Real-timePCR验证249干扰位点的干扰序列对半乳凝素1基因干扰效果最佳,并以此进行后续的体内实验;(2)与正常对照组相比,哮喘模型组肺泡和气道周围有大量的炎症细胞聚集,以嗜酸性粒细胞为主;骨髓间充质干细胞组或重组半乳凝素1蛋白组气道及肺泡灌洗液中炎症细胞显著减少,而半乳凝素1基因干扰的骨髓间充质干细胞输注对哮喘小鼠气道及肺泡灌洗液炎症细胞聚集无明显影响;(3)结果表明骨髓间充质干细胞分泌的半乳凝素1对哮喘小鼠气道炎症有明显的抑制作用。

BACKGROUND: Our previous studies have demonstrated that bone marrow mesenchymal stem cells can ameliorate airway inflammation and regulate levels of inflammatory factors. Moreover, galectin-1 secreted by bone marrow mesenchymal stem cells can inhibit the immune function of dendritic cells in vitro. However, the effect of galectin-1 secreted by bone marrow mesenchymal stem cells on asthma is unknown.OBJECTIVE: To investigate the effect of galectin-1 secreted by bone marrow mesenchymal stem cells on airway inflammation of asthmatic mice.METHODS: A recombinant lentiviral vector, pLVX-gal-1-shRNA, was constructed for RNA interference of galectin-1 gene and then was transferred into bone marrow mesenchymal stem cells. Forty female BALB/c mice were equally randomized into normal control group,asthmatic group, bone marrow mesenchymal stem cells treatment group(cell treatment group), galectin-1 treatment group and galectin-1 interference group. The number of total inflammatory cells and differential cells in the mouse bronchoalveolar lavage fluid was determined.Furthermore, hematoxylin-eosin staining was used to compare airway inflammation among five groups.RESULTS AND CONCLUSION: Four short-hairpin RNA sequences targeting mouse galectin-1 mRNA were designed. A real time-quantitative polymerase chain reaction demonstrated that bone marrow mesenchymal stem cells were inhibited most by interference site249 RNA sequences which were later used in vivo study. Accumulation of inflammation cells, particularly eosinophils, around the airway and in the bronchoalveolar lavage fluid was evidence in asthmatic mice compared to the normal control group. However, bone marrow mesenchymal stem cells engraftment or protein of galectin-1 infusion significantly reduced inflammatory infiltration both in the airway and in the bronchoalveolar lavage fluid. Moreover, eosinophils in the bronchoalveolar lavage fluid and in the airway attenuated dramatically in the cell treatment group and galectin-1 treatment group. However, there was no effect on inflammation accumulation in the bronchoalveolar lavage fluid and airway by infusion of galectin-1-transfected bone marrow mesenchymal stem cells to asthmatic mice. These results indicate that galectin-1 secreted by bone marrow mesenchymal stem cells could alleviate airway inflammation in the asthmatic mouse.