Effect of MiR-16 on Acute Lung Injury in Neonatal Rats Through Regulating NF-κB Pathway

Abstract

Acute lung injury represents a widespread, variable type of lung injury characterized by a low oxygen level in the blood, non cardiogenic pulmonary edema, low lung compliance and extensive capillary leakage. In our study, the Wistar rat mode of ALI was established using lipopolysaccharide (LPS). The rats were randomly divided into normal control (NC) group (n = 12) and miR-16 overex-pression group (n = 12), and they were transfected with empty vector and miR-16 overexpression virus, respectively. The lung tissues were extracted in both groups, and then the expression levels of miR-16 and NF-κB were detected via fluorescence quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and the association between their expressions was analyzed via Pearson correlation analysis. Moreover, the morphological changes in lung tissues were detected via hematoxylin-eosin (HE) staining, and the differences in the wet/dry weight (W/D) ratio and the pathomorphological score of lung tissues were compared between the two groups. The expression level of NF-κB was detected via immunohistochemistry (IHC) and Western blotting. Our results showed that, there were different degrees of lung injury in lung tissues in both groups. In miR-16 overexpression group, the W/D ratio was significantly higher than that in NC group (P < 0.05), and the pathomorphological score was also significantly higher than that in NC group (P < 0.05). The results of RT-PCR revealed that the mRNA levels of miR-16 and NF-κB in miR-16 overexpression group were 2.5 and 3.7 times higher than those in NC group. The results of Western blotting and IHC also showed that the activity of NF-κB in lung tissues was evidently enhanced in miR-16 overexpression group compared with that in NC group. According to the Pearson correlation analysis, there was a significant positive correlation between the mRNA levels of miR-16 and NF-κB in lung tissues (r = 0.705, P = 0.012). In conclusion, miR-16 activates the NF-κB pathway to initiate a series of inflammatory responses, thereby contributing to the occurrence of ALI in rats.