MicroRNA-186 promotes macrophage lipid accumulation and secretion of pro-inflammatory cytokines by targeting cystathionine γ-lyase in THP-1 macrophages

• Published in: Atherosclerosis 2016-07, Vol.250, p.122-132
• Main Authors: Yao, Yan, Zhang, Xin, Chen, Hai-peng, Li, Liang, Xie, Wei, Lan, Gang, Zhao, Zhen-wang, Zheng, Xi-Long, Wang, Zong-bao, Tang, Chao-ke
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions; Alleles; Cardiovascular; Cystathionine gamma-Lyase - genetics; Cystathionine gamma-Lyase - metabolism; Cystathionine γ-Lyase; Cytokines - metabolism; HEK293 Cells; Humans; Hydrogen sulfide; Hydrogen Sulfide - chemistry; Inflammation; Interleukin-6 - metabolism; Leukocytes, Mononuclear - cytology; Lipids - chemistry; Lipoprotein lipase; Lipoprotein Lipase - metabolism; Macrophages - metabolism; MicroRNAs - genetics; MicroRNAs - physiology; miR-186; Myocytes, Cardiac - metabolism; Signal Transduction; THP-1 Cells
• ISSN: 0021-9150; 1879-1484
• DOI: 10.1016/j.atherosclerosis.2016.04.030

Abstract Background and aims Several studies suggest that cardiomyocyte-enriched miR-186 is involved in cardiac injury and myocardial infarction, and also plays an important role in atherosclerotic diseases, but the underlying mechanism is unknown. Cystathionine-γ-lyase (CSE) is the predominant enzyme to produce H2 S in the cardiovascular system. Here, miR-186 was identified to bind to the 3′UTR of CSE. In this study, we aimed at exploring whether miR-186 affects lipid accumulation and secretion of pro-inflammatory cytokines by targeting CSE and its underlying mechanism in human THP-1 macrophages and peripheral blood monocyte-derived macrophages (PBMDM). PBMDM just as a control group for the comparison with the THP-1 macrophages. Methods MiR-186 target genes, CSE 3′UTR sequence and free energy were predicted and analyzed by bioinformatics analyses and dual-luciferase reporter assays. The expression of CSE mRNA and protein were measured by real-time quantitative PCR and western blot analyses. The lipid accumulation in THP-1 macrophages was detected by high performance liquid chromatography (HPLC). The effects of miR-186 on secretion of IL-6, IL-1β and TNF-α were examined by ELISA. Endogenous H2 S was detected by spectrophotometry. Using small interfering RNA (siRNA) approach to decrease the expression of CSE protein and mRNA. Results We found that miR-186 directly inhibited CSE protein and mRNA expression through targeting CSE 3′UTR by bioinformatics analyses and dual-luciferase reporter assays. HPLC assays showed that miR-186 increased the lipid accumulation in human THP-1 macrophages. We also showed that miR-186 enhanced secretion of pro-inflammatory cytokines in human THP-1 macrophages. Using siRNA approach, we found that CSE siRNA could inhibit the miR-186 inhibitor-induced decrease in the expression of LPL protein and mRNA in human THP-1 macrophages, which was accompanied a decrease in the level of H2 S. Conclusions MicroRNA-186 promotes macrophage lipid accumulation and pro-inflammatory cytokine secretion by targeting cystathionine γ-lyase in THP-1 macrophages.