Abstract: Objective To detect the role of miR-34a on macrophage inflammation and polarization under high glucose conditions. Methods Mouse macrophages were collected and cultured during high glucose for 3-28 days. RT-qPCR was used to detect the expression of miR-34a, iNOS, MCP-1 and Arg-1 mRNA. Then miR-34a was over-expressed or silenced, ELISA was used to detect the expression of IL-6, IL-1β,TNF-α and qRT-PCR was used to detect the expression of iNOS and MCP-1 mRNA. Western blot was used to detect the expression of Notch1. Results Expression of miR-34a increased under high glucose conditions in RAW264.7 cells continuously. Over-expression of miR-34a promoted the expression of MCP-1 and iNOS observed by RT-qPCR and increased the expression of IL-6, IL-1β and TNF-α detected by ELISA. Further studies showed that siRNA-Notch1 down-regulated the expression of miR-34a, MCP-1, iNOS, IL-6, IL-1β and TNF-α. Conclusions Chronic high glucose condition stimulates the expression of miR-34a which promotes M1 macrophage polarization and releasing of pro-inflammatory factors.

Key words: miR-34a, macrophage, high glucose, polarization, inflammation