Abstract: Objective The miRNA expression profiling in different lung tissue of COPD dynamic rat model was established. The differential expression miRNAs were analysed by bioinformatics methods.This study is aimed at finding the variety rule of miRNAs and possibly refer to the correlate pathogenesis of COPD. Methods 1 The rats were randomly divided into the control group; the cigarette smoking (CS) for 2、4、6、8w group and 15w plus elastase-treated group. Each group had five rats. Morphological changes of the lungs were performed through pathology observation. 2 The lung tissue of control group、CS for 4w group and 15w plus elastase-treated group（each group had two rats）were analysed by miRNA microarray. 3 The dysregulated miRNAs were detected by qRT-PCR for the further confirming of microarray data. 4 The miRNA expression profiling was analysed by bioinformatics methods including target prediction and unsupervised hierarchical clustering analysis.Results 1 COPD dynamic rat model were established successfully. The dynamic pathology changes in the lung tissue of this model were inflammatory infiltrates in early stage and emphysema in late stage. 2 The dynamic miRNA expression profiling was established. There were 30 and 37 differentially expressing miRNAs in the lungs of rats with 4w group and 15w group respectively. 3 Further qRT-PCR indicated that the relative expression levels of miR-146a, miR-21, miR-206 and miR-181a were consistent with the microarray data. 4 The differential expression miRNAs may be closely related to the pathogenesis of COPD through bioinformatics analysis. Conclusions：1 The dynamic rats models of COPD and miRNA expression profiling were established successfully. 2 The differential expression miRNAs may play important role in the pathogenesis of COPD through bioinformatics analysis.

Key words: Chronic obstructive pulmonary disease (COPD), miRNA, microarray, Bioinformatics