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

Abstract

Jie Zhang,1,* Zhongneng Xu,2,* Lianhua Kong,3,* Hong Gao,1 Yueming Zhang,1 Yulong Zheng,1 Yufeng Wan1 1Department of Respiratory Diseases, The Affiliated Huai’an Hospital of Xuzhou Medical University, Huai’an 203302, Jiangsu, People’s Republic of China; 2Department of Cardiothoracic Surgery, Huai’an Hospital Affiliated to Nanjing Medical College and Huai’an First People’s Hospital, Huai’an 223002, Jiangsu, People’s Republic of China; 3Department of Infectious Disease, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yufeng Wan; Yulong Zheng Tel [phone]Email [email protected]; [email protected]: The aim of this study was to investigate the role of miRNA-486-5p 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 miR-486-5p, were determined using qPCR or Western blotting. Luciferase reporter assays and fluorescence in situ hybridization were used to confirm the regulatory interaction between miR-486-6p and HAT1.Results: miR-486-5p 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 miR-486-5p directly targeted HAT1, and cellular localization showed that miR-486-5p and HAT1 were highly expressed in the cytoplasm. miR-486-5p overexpression led to a significant upregulation of TLR4 and a significant downregulation of HAT1. Inversely, miR-486-5p inhibition led to a significant downregulation of TLR4 and a significant upregulation of HAT1. HAT1 knockdown using siRNA significantly upregulated the expression of TLR4, IL-6, IL-8, TNF-α, and IFN-γ.Conclusion: miR-486-5p was differentially expressed in the alveolar macrophages of COPD patients. miR-486-5p overexpression may enhance the TLR4-triggered inflammatory response in COPD patients by targeting HAT1.Keywords: smoking, chronic obstructive pulmonary disease, miR-486-5p, toll-like receptor 4, histone acetyltransferase 1

Keywords

• smoking
• chronic obstructive pulmonary disease
• mir-486-5p
• toll-like receptor 4
• histone acetyltransferase 1