miRNA-486-5p Promotes COPD Progression by Targeting HAT1 to Regulate the TLR4-Triggered Inflammatory Response of Alveolar Macrophages.

PURPOSE

The aim of this study was to investigate the role of in chronic obstructive pulmonary disease (COPD) progression and the underlying molecular mechanisms.

MATERIALS AND METHODS

Aberrant miRNA expression profiles between smokers and nonsmokers, and those between COPD patients and normal subjects were analyzed using microarray datasets and reverse-transcriptase quantitative polymerase chain reaction (qPCR). Enzyme-linked immunosorbent assay was used to determine the levels of inflammatory cytokines in cell supernatants. Expression levels of inflammatory cytokines, HAT1, TLR4, and , were determined using qPCR or Western blotting. Luciferase reporter assays and fluorescence in situ hybridization were used to confirm the regulatory interaction between and .

RESULTS

was significantly upregulated in the COPD and smoker groups compared to the control group, as demonstrated using bioinformatics analysis and validated using qPCR assay of alveolar macrophages and peripheral monocytes. Moreover, miR-486-5p expression was significantly correlated with the expression of IL-6, IL-8, TNF-α, and IFN-γ. Luciferase reporter assays confirmed that directly targeted , and cellular localization showed that and HAT1 were highly expressed in the cytoplasm. overexpression led to a significant upregulation of TLR4 and a significant downregulation of HAT1. Inversely, inhibition led to a significant downregulation of TLR4 and a significant upregulation of HAT1. knockdown using siRNA significantly upregulated the expression of TLR4, IL-6, IL-8, TNF-α, and IFN-γ.

CONCLUSION

was differentially expressed in the alveolar macrophages of COPD patients. overexpression may enhance the -triggered inflammatory response in COPD patients by targeting .