Figure 8.

miR-146a regulates macrophage polarization. Representative Western blots (A) and their quantitative data (B) show protein levels of proinflammatory M1 markers TNF-α, iNOS, and IL-1β were significantly increased, but anti-inflammatory M2 marker YM1 was decreased in splenic tissues isolated from diabetic db/db mice. However, treatment of diabetic db/db mice with miR-146a mimics completely reversed diabetes-increased M1 marker proteins and -reduced M2 marker protein compared with cel–miR-67 mimic treatment. C: Whole spleen cell suspensions were labeled with antibodies against macrophage lineage markers (F4/80 and CD11b), and lineage F4/80⁺CD11b⁺ cells were sorted by FACS. Dot plots correspond to a representative staining in the splenocytes with gates used for sorting. D: Total RNAs from sorted splenic macrophages were analyzed by real-time RT-PCR for TNF-α, iNOS, IL-1β, and YM1; values are relative to expression of the gene encoding β-actin. The miR-146a treatment reduces serum IL-1β (E) and TNF-α (F) concentrations analyzed via ELISA in diabetic mice compared with mice treated with control (con) miR. *P < 0.05 and **P < 0.01 compared with nondiabetic db/m mice; #P < 0.05 and ##P < 0.01 compared with diabetic db/db mice treated with control cel–miR-67.