Molecular hydrogen regulates the expression of miR-9, miR-21 and miR-199 in LPS-activated retinal microglia cells

·AIM: To explore the potential mechanism of molecular hydrogen in the regulation of miRNA expression and signal-modulating activities. ·METHODS: Retinal microglia cells were activated by Lipopolysaccharides (LPS) and then treated with hydrogen -saturated medium or normal medium without hydrogen. qRT -PCR was used to detect the expression difference in miR-9, miR-21 and miR-199 between these two groups. Moreover, the expression of LPS -induced signaling proteins, including Myd88, IKK -β, NF -kB, and PDCD4, were detected by Western blotting. ·RESULTS: The results demonstrated a marked downregulation of miR -9 and miR -21 and up -regulation of miR-199 by hydrogen treatment; the expression of Myd88 and IKK-β was decreased after hydrogen treatment, whereas PDCD4 was increased, and there was no significant change in NF-kB expression. · CONCLUSION: The results in the present study indicate that miR -9, miR -199 and miR -21 play an important role in the anti -inflammatory regulation of LPS -activated microglia cells by molecular hydrogen, which will help to explain the protective mechanism of molecular hydrogen against inflammatory injury.·