Microcystin-LR prenatal exposure induces coronary heart disease through macrophage polarization imbalance mediated by trophoblast-derived extracellular vesicles.

Trophoblast-derived extracellular vesicles (T-EVs) increase during pregnancy and act as a critical signal in macrophage polarization. However, MC-LR significantly affected the miRNA expression profile of T-EVs. Upon internalization into macrophages, T-EVs-derived miR-377-3p specifically targets the 3’UTR region of NR6A1 to inhibit the gene expression. Silencing of transcription suppressor NR6A1 leads to abnormal activation of the downstream mTOR/S6K1/SREBP pathway, inducing metabolic reprogramming and ultimately leading to M1 polarization of macrophages. HTR-8/Svneo cells cultured in exosomes free medium were treated with 0 or 1 μM MC-LR (A-LR-M001, TAIWAN ALGAL SCIENCE INC) for 24 h, after which the cell culture medium was collected for T-EVs extraction by differential centrifugation (300 g/10 min, 2000 g/20 min, 10000 g/30 min and 100000 g/70 min).Then the RNA was extracted for miRNA sequencing