哮喘小鼠CD34+祖细胞和嗜酸性粒细胞的动态变化及其与CCR3/eotaxin表达的关系

目的 观察不同时间点CD34+祖细胞和嗜酸性粒细胞在哮喘小鼠支气管肺泡灌洗液(BALF)、外周血、骨髓悬液中的动态变化过程，探讨CD34+祖细胞、嗜酸性粒细胞、CCR3/eotaxin与哮喘小鼠肺部炎症的关系。 方法 以C57BL/6小鼠为研究对象，以卵白蛋白作为抗原建立哮喘模型，于最后一次抗原激发后6、12、24、48 h检测BALF、外周血和骨髓中的嗜酸性粒细胞、CD34+祖细胞、eotaxin的变化，检测CD34+祖细胞上CCR3的表达；行肺组织病理切片观察嗜酸性粒细胞浸润；PCR检测肺组织CCR3和eotaxin mRNA水平。 结果 抗原激发后嗜酸性粒细胞数、CD34+细胞数、CD34+/CCR3+细胞数在BALF、外周血、骨髓悬液中有不同程度的增加。模型组BALF的eotaxin水平在抗原激发后6 h与对照组相比有明显增加(P<0.05)，并一直持续到24 h。外周血和骨髓悬液中eotaxin水平与对照组相比差异无统计学意义(均P>0.05)。模型组各时间点肺组织eotaxin mRNA和CCR3 mRNA的表达与对照组相比均有明显增加。BALF中嗜酸性粒细胞数分别与骨髓悬液中嗜酸性粒细胞数、CD34+/CCR3+细胞数呈正相关，而与骨髓悬液中CD34+细胞数无明显相关性。 结论 ①哮喘小鼠气道局部嗜酸性粒细胞增多与骨髓CD34+祖细胞上CCR3表达上调有关。②CCR3/eotaxin参与CD34+祖细胞分化和趋化，与哮喘小鼠气道嗜酸性粒细胞浸润密切相关。 

Dynamic changes of CD34+ progenitor cells and eosinophils in asthmatic mice and their relationship with CCR3/eotaxin expression

Objective The dynamic changes of eosinophils, CD34+ progenitor cells, eotaxin and CCR3 expression in BALF, peripheral blood, bone marrow suspension of asthmatic mice were studied by asthma model. This study aims to investigate the relationship between airway eosinophil inflammation and CD34+ progenitor cells and CCR3/eotaxin in asthmatic mice. Methods C57BL/6 mice were used to establish asthma model with ovalbumin as antigen. The changes of eosinophils, CD34+ progenitor cells and eotaxin in BALF, peripheral blood and bone marrow were detected 6 hours, 12 hours, 24 hours and 48 hours after the last antigen challenge, and the expression of CCR3 on CD34+ progenitor cells was detected. Lung biopsy was used to observe eosinophil infiltration. Lung tissue CCR3 and eotaxin mRNA levels were detected by PCR. Results The results showed that eosinophils, CD34+ cells and CD34+/CCR3+ cells were increased in BALF, peripheral blood and bone marrow suspension. The eotaxin level of BALF in the model group increased significantly at 6 h compared with the control group (P<0.05), and lasted until 24 h. The level of eotaxin in peripheral blood and bone marrow suspension was not significantly different from that in the control group (all P>0.05). The expression of eotaxin mRNA and CCR3 mRNA in lung tissue of model group increased significantly at each time point compared with control group. The number of eosinophils in BALF was positively correlated with the number of eosinophils and CD34+/ CCR3+ cells in bone marrow, but not with the number of CD34+ cells in bone marrow. Conclusion ①The increase of eosinophils in airway of asthmatic mice is related to the up-regulation of CCR3 expression in bone marrow CD34+ progenitor cells. ②CCR3/eotaxin participates in the differentiation and chemotaxis of CD34+ progenitor cells. It is closely related to airway eosinophil infiltration in asthmatic mice.