miR-214-3p inhibits LPS-induced macrophage inflammation and attenuates the progression of dry eye syndrome by regulating ferroptosis in cells

Dry eye disease (DED) is an ocular illness caused by insufficient tear secretion or poor tear quality, and inflammation is a key factor in its pathogenesis. Previous studies have shown that miRNAs are important regulatory factors in DED.

The purpose of this study was to explore the potential mechanism by which miR-214-3p influenced the DED process by regulating the macrophage inflammatory response.

We induced THP-1 cells to differentiate into M0 macrophages with 100 ng/mL phorbol-12-myristate-13-acetate (PMA) and then added 15 ng/mL lipopolysaccharide (LPS) to induce inflammation. The expression of related genes and proteins was detected via RT‒qPCR, Western blotting, ELISA and immunofluorescence staining; cell viability was measured using the CCK-8 assay; and flow cytometry was used to detect ROS levels.

In tear and serum samples from DED patients, the levels of miR-214-3p, IL-10, and Arg1 were decreased, and the levels of IL-6, TNF-α, IL-1β, and iNOS expression were increased. Moreover, the overexpression of miR-214-3p attenuated the effect of LPS and inhibited M1 polarization and inflammation in macrophages. Mechanistically, miR-214-3p inhibited macrophage ferroptosis by downregulating TFRC expression, thereby inhibiting macrophage M1 polarization and inflammation and alleviating the progression of DED.

Our study indicated that the upregulation of miR-214-3p expression might be a new target for DED therapy.