miR-432-5p Targeting SORT1 to Protect Artery Smooth Muscle Cells and Inhibit Coronary Artery Disease

Recent studies highlight the crucial role of microRNAs (miRNAs) in coronary artery disease (CAD). This retrospective study investigated the abundance of miR-432-5p in the serum of CAD patients and explored its role. 252 volunteers were included. The levels of miR-432-5p and Sortilin 1 (SORT1) in the serum of CAD patients and oxidized low-density lipoprotein (ox-LDL)-treated human arterial smooth muscle cells (HASMCs) were quantified via qRT-PCR. The correlation coefficient, clinical diagnostic performance, and risk factors were analyzed with Pearson correlation, receiver operating characteristic (ROC) curve, and binomial logistic regression, respectively. HASMC proliferation, migration, and apoptosis were evaluated using Cell Counting Kit-8 (CCK-8), transwell, and flow cytometry assay, respectively. Potential binding sites between miR-432-5p and SORT1 were predicted with TargetScan and validated through dual-luciferase reporter assay and co-transfection experiments. Serum miR-432-5p was decreased, while SORT1 was elevated in CAD patients and ox-LDL-induced HASMCs. miR-432-5p showed a negative correlation with total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), and Gensini score. miR-432-5p and SORT1 effectively distinguished CAD patients from controls based on ROC analysis. miR-432-5p and SORT1 serve as independent risk predictors. Restoration of miR-432-5p reversed ox-LDL-induced increases in HASMC proliferation and migration and restored apoptosis levels. SORT1 was confirmed as a direct target of miR-432-5p, and its upregulation counteracted the protective effects of miR-432-5p on HASMC under ox-LDL exposure. This study suggests that miR-432-5p protects HASMCs and inhibits coronary artery disease progression by targeting SORT1, positioning both miR-432-5p and SORT1 as potential biomarkers for CAD.