LncRNA SNHG16 promoted proliferation and inflammatory response of macrophages through miR-17-5p/NF-κB signaling pathway in patients with atherosclerosis

OBJECTIVE: Atherosclerosis (AS) is a leading cause of cardiovascular disease (CVD), which is also the leading reason for mortality and morbidity worldwide. Growing evidence has shown that long non-coding RNAs (lncRNAs) play some roles in the development of AS; however, their roles remain unclear. In this study, we aimed to explore the function of lncRNA SNHG16 in AS. PATIENTS AND METHODS: qRT-PCR was used to detect the expressions of SNHG16 and miR-17-5p in AS serum samples and THP-1 macrophage-derived foam cells; the correlations were also analyzed. THP-1 macrophages were respectively treated with ox-LDL and several inflammatory factors to explore the affecting factors. What's more. SNHG16 overexpression lentivirus (LV-SNHG16) and downregulation lentivirus (LV-sh SNHG16) were purchased and infected into THP-1 macrophages. CCK8 assay was used to measure cell proliferation; the levels of IKK beta, p-IkBa and p-p65 were detected by western blot (WB), and the levels of TNF-alpha, IL-1 beta and IL-6 were detected by ELISA kit. Moreover, the luciferase assay was performed to explore the binding site of SNHG16 and miR-17-5p. Furthermore, we transfected miR-17-5p mimic and inhibitor into THP-1 macrophages; the proliferation, NF-kappa B signaling pathway factors and inflammatory factors were detected. Finally, JSH, a NF-kappa B signaling inhibitor, was added into LV-SNHG16 THP-1 macrophages and miR-17-5p inhibitor was transfected into LV-sh SNHG16 THP-1 macrophages to confirm that SNHG16 functions via miR-17-5p/NF-kappa B signaling pathway. RESULTS: We found that SNHG16 was increased in AS patients and THP-1 macrophage-derived foam cells. Additionally, SNHG16 was increased in THP-1 macrophages by ox-LDL with time-dependence and dose-dependence. Furthermore. SNHG16 overexpression promoted proliferation, inflammatory response and increased levels of IKK beta, p-IkBa, p-p65 in THP-1 macrophages, while SNHG16 downregulation led to the opposite results. Most important- ly, we found that miR-17-5p expressions were significantly decreased in AS patients. which were negatively correlated with SNHG16. Luciferase gene reporter assay confirmed that SNHG16 could directly bind with miR-17-5p. Moreover, the proliferation, inflammatory factors and NF-kappa B signaling factors were significantly repressed after transfecting miR-17-5p mimic into THP-1 macrophages, while it led to the opposite results after transfecting miR-17-5p inhibitor. Then, we added JSH, a NF-kappa B signaling inhibitor, into LV-SNHG16 THP-1 macrophages; as a result, the increased cell proliferation rate and inflammatory response were both decreased. Finally, we found that the repressed cell proliferation, inflammatory factors and expressions of NF-kappa B signaling factors in LV-sh SNHG16 group were increased after co-transfected with miR-175p inhibitor. CONCLUSIONS: According to the results, we found that SNHG16 was upregulated in AS patients. Furthermore, we firstly found that SNHG16 was increased by ox-LDL in THP-1 macrophages. Most importantly, we uncovered a previously unappreciated SNHG16/miR-17-5p/NF-kappa B signaling axis in promoting proliferation and inflammatory response in AS patients and THP-1 macrophages, which might provide a potential target for treating AS.