Silencing of MEG3 inhibited ox-LDL-induced inflammation and apoptosis in macrophages via modulation of the MEG3/miR-204/CDKN2A regulatory axis.

Atherosclerosis (AS) is one of the most common chronic inflammatory diseases and a major cause of morbidity and mortality. However, the underlying molecular mechanisms of the progression of AS are still largely unknown. Increasing evidence has demonstrated that long noncoding RNAs (lncRNAs) play important roles in a variety of biological processes and the physiological and pathological progression of human diseases. In this study, we aimed to explore the role and underlying molecular mechanism of lncRNA MEG3 in Raw264.7 cells treated with oxidized low-density lipoprotein (ox-LDL). First, we found that ox-LDL inhibited the cell viability and proliferation, increased TNF alpha and IL1 beta secretion and induced the apoptosis of Raw264.7 cells. Second, we demonstrated that ox-LDL upregulated MEG3 expression and that knockdown of MEG3 inhibited the action of ox-LDL in Raw264.7 cells. Third, we showed that MEG3 sponged miR-204 in Raw264.7 cells treated with ox-LDL. Fourth, we demonstrated that miR-204 regulated the expression of cyclin-dependent kinase inhibitor 2A (CDKN2A) in Raw264.7 cells treated with ox-LDL. Finally, we revealed that MEG3 exerted its function via the regulation of the MEG3/miR-204/CDKN2A regulatory axis in Raw264.7 cells treated with ox-LDL. In summary, our study identified the role of the MEG3/miR-204/CDKN2A pathway in Raw264.7 cells treated with ox-LDL, revealed a novel regulatory pathway in AS and indicated potential novel characteristic biomarkers and therapeutic targets for AS.