MicroRNA-325 facilitates atherosclerosis progression by mediating the SREBF1/LXR axis via KDM1A

Aims: MicroRNA-325 (miR-325) was significantly upregulated in diabetic atherosclerosis, while its specific role in atherosclerosis has not been established. The present study was set to probe the effects of miR-325 on the atherosclerosis progression and to explore the mechanisms.

Materials and methods: The ApoE^-/- mouse with atherosclerosis was developed to detect the miR-325 expression in atherosclerotic plaques. The pathological symptoms of atherosclerotic mice were observed by injection of miR-325 mimic or inhibitor. Subsequently, the levels of CRP, IL-6, IL-1β and TNF-ɑ in mouse serum were measured by ELISA. Then, miR-325 was overexpressed or silenced in RAW264.7-derived foam cells (FCs), and Cholesterol efflux and lipid content were evaluated. Furthermore, miR-325 expression was altered in HA-VSMCs to measure viability and Apoptosis. The targets of miR-325 were predicted in a bioinformatics website, and the expression of KDM1A, SREBF1 and PPARγ-LXR-ABCA1 in mouse arterial tissues and cells was detected, followed by rescue experiments.

Key findings: miR-325 was elevated in arterial tissues of atherosclerotic mice, and miR-325 inhibition in mice reduced the contents of total Cholesterol, triglyceride, low-density lipoprotein, and CRP, IL-6, IL-1β and TNF-ɑ levels in mouse serum. miR-325 inhibitor facilitated the Cholesterol efflux and decreased the lipid content in RAW264.7 cells, and also diminished HA-VSMC viability. miR-325 targeted KDM1A to reduce SREBF1 expression, and further KDM1A suppression inhibited Cholesterol efflux in RAW264.7 cells and the activation of PPARγ-LXR-ABCA1 pathway.

Significance: miR-325 lowers SREBF1 expression by decreasing KDM1A expression, thereby inhibiting the activation of the PPARγ-LXR-ABCA1 pathway and thus promoting atherosclerosis.