Circ_0000345 Protects Endothelial Cells From Oxidized Low-Density Lipoprotein-Induced Injury by miR-129-5p/Ten-Eleven Translocation Axis

Oxygenized Low-Density Lipoprotein-Induced ASMC Dysregulation Depends on circ_0000345-Mediated Regulatory Mechanism

AIMS

Vascular smooth muscle cells are key participants in atherosclerosis. Circular RNA hsa_circ_0000345 (circ_0000345) and miR-647 are related to oxygenized low-density lipoprotein (ox-LDL)-induced arterial smooth muscle cell (ASMC) dysregulation. However, the relationship between circ_0000345 and miR-647 in ox-LDL-induced ASMC dysregulation is unclear.

METHODS

Relative levels of circ_0000345, miR-647, and PAP-associated domain containing 5 (PAPD5) mRNA in AS patient's serum and ox-LDL-induced ASMCs were detected via RT-qPCR. Gain-of-function experiments were utilized to analyze the effects of circ_0000345 upregulation on ox-LDL-induced cell proliferation, migration, invasion, and inflammatory response in ASMCs. The relationship between circ_0000345 or PAPD5 and miR-647 was validated by dual-luciferase reporter and RNA immunoprecipitation assays.

RESULTS

Circ_0000345 and PAPD5 were lowly expressed in AS patient's serum and ox-LDL-induced ASMCs, while miR-647 expression had an opposing trend. Mechanistically, circ_0000345 was verified as a miR-647 sponge, and miR-647 overexpression impaired the inhibitory effects of circ_0000345 upregulation on ox-LDL-induced ASMC proliferation, migration, invasion, and inflammatory response. Further experiments demonstrated that PAPD5 was a miR-647 target, and circ_0000345 adsorbed miR-647 to mediate PAPD5 expression. Also, PAPD5 inhibition relieved miR-647 silencing-mediated suppression on ox-LDL-induced ASMC proliferation, migration, invasion, and inflammatory response.

CONCLUSIONS

Circ_0000345 elevated PAPD5 expression via acting as a miR-647 sponge, resulting in alleviating ox-LDL-induced ASMC dysregulation. The study highlighted the critical role of circ_0000345 in AS.

Knockdown of NCK1-AS1 inhibits the development of atherosclerosis by targeting miR-1197/COX10 axis

BACKGROUND

Although long non-coding RNA (lncRNA) NCK1-AS1 plays important roles in human cancer, its function in atherosclerosis (AS) remains unclear.

METHOD

The expression of NCK1-AS1 in AS blood samples was detected by qRT-PCR. Oxidized low-density lipoprotein (ox-LDL) was used to construct the AS cell model, and quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to evaluate NCK1-AS1 level. Cell phenotypes including proliferation and apoptosis were assessed by Cell Counting Kit-8 (CCK-8) assay and flow cytometer, respectively. The malondialdehyde level was measured to evaluate oxidative stress. The expression of apoptosis-related proteins was evaluated by western blot. The expression of inflammatory cytokines (IL-1β, IL-6 and TNK-α) was measured by qRT-PCR and ELISA assays. The relationship among NCK1-AS1, miR-1197 and COX10 was determined by bioinformatic analysis and luciferase reporter assay.

RESULTS

NCK1-AS1 was significantly upregulated in AS blood samples and ox-LDL stimulated vascular smooth muscle cells (VSMCs). Knockdown of NCK1-AS1 increased cell viability, reduced cell apoptosis and MDA level, and also inhibited the expression of inflammatory cytokines (IL-1β, IL-6 and TNK-α) in ox-LDL stimulated VSMCs. NCK1-AS1 could positively regulate COX10 expression by directly sponging miR-1197. Moreover, co-transfection of sh-NCK1-AS1 and miR-1197 inhibitor, or co-transfection of sh-NCK1-AS1 and pc-COX10 (COX10 overexpressing plasmid) obviously reduced cell viability, promoted cell apoptosis, and increased MDA level in VSMCs followed by ox-LDL treatment for 24 h compared to that in sh-NCK1-AS1 transfected VSMCs.

CONCLUSION

Our study revealed that knockdown of NCK1-AS1 attenuated the development of AS by regulating miR-1197/COX10 axis, suggesting that this lncRNA might be a potential therapeutic target for AS.