Effects of different experimental approaches on the expression of microRNA of alveolar macrophages in rats with chronic obstructive pulmonary disease / 解放军医学杂志

ABSTRACT

Objective To compare the different expressions of miRNAs of alveolar macrophages (AM) in two chronic obstructive pulmonary disease (COPD) models of rat induced by smudging alone or combined with lipopolysaccharide (LPS) infusion. Methods Sixty female Wistar rats were randomly assigned into 4 groups control group I, control group II, COPD model group I (cigarette smoke exposure alone, CS) and COPD model group II (cigarette smoke exposure + LPS infusion, CS+LPS). COPD rat models were evaluated by chest CT, lung function test and histopathological examination of lungs. The primary AM were acquired and the RNAs were then extracted after carrying out bronchoalveolar lavage. Three pairs of samples were used for detection of miRNAs expression by the method of miRNA microarray chip. The difference was verified by qRT-PCR analysis on another 5 pairs of samples. Data analysis was performed to find out the significantly differential miRNAs expression profiles in COPD rat models. Results The chest CT, lung function test and histopathological examination verified the COPD in rats of CS and CS+LPS groups. Compared with control group I, the expressions of let-7b-3p, miR-376c-3p and miR-675-5p were downregulated in CS group with no miRNAs up-regulated. Compared with control group I, the expressions of let-7b-3p and miR-675-5p were down-regulated, while the expressions of 11 miRNAs were obviously up-regulated in CS+LPS group as miR-200b-3p, miR-665, miR-344b-1-3p, miR-34c-5p, miR-34b-5p, miR-99b-5p, miR-129-1-3p, miR-3557-5p, miR-331-5p, miR-493-5p and miR-200a-3p. Conclusions COPD rat models are established successfully both with CS and CS+LPS. The results of chest CT, lung function test and histopathological examination have shown no significant difference between the two approaches. However, the expressions of miRNAs of AM are significantly different.