MicroRNA miR-212-5p Regulates the MEK/ERK Signaling Pathway by Targeting A-Raf proto-oncogene...

Objective: To investigate the role of miR-212-5p-targeted ARAF during the apoptosis of rat alveolar macrophages induced by cowshed PM_2.5. Methods: miRNA and related target genes and pathways were predicted using the KEGG, TargetScan, and other prediction websites. NR8383 macrophages were treated with cowshed PM_2.5 to establish an in vitro lung injury model in rats; meanwhile, for the assessment of cell viability, apoptosis, intracellular calcium ions, and mitochondrial membrane potential in NR8383 cells, RT-qPCR was used to detect the expression of miR-212-5p and the target gene ARAF. Results: The bioinformatic analyses showed that miR-212-5p and ARAF were involved in PM_2.5-associated cellular damage. Exposure to different concentrations (0 μg/mL, 60 μg/mL, 180 μg/mL, 300 μg/mL) with different durations (0 h, 12 h, 24 h, 48 h) of cowshed PM_2.5 resulted in apoptosis, increased intracellular calcium ions, and decreased mitochondrial membrane potential. The miR-212-5p mimic group showed an up-regulation of Bax and cleaved Caspase 3 expression but decreased Bcl2 expression compared to the NC group, and overexpression of ARAF up-regulated the expression of p-MEK1/2 and p-ERK1/2 and simultaneously reversed the above phenomena. Conclusions: miR-212-5p targets ARAF to affect the cowshed PM_2.5-induced apoptosis through the MEK/ERK signaling pathway, providing a potential target for relevant farming industry and pathology studies.