Figure 3.

Macrophages play a critical role in miR-155 deficiency-mediated suppression of dextran sulfate sodium (DSS)-induced colitis. WT (n = 3) or miR-155^−/− (n = 3) mice were given 3% DSS in drinking water for 5 days, followed by regular drinking water for 6 days. (A) Total RNA was extracted from colon tissues and analyzed by the mouse miR-155 Targets RT² Profiler PCR Array (Qiagen), and the most differentially expressed target genes were ranked. (B–D) WT (n = 12) or miR-155^−/− (n = 13) mice were administrated intravenously with clodronate-liposomes (MDP) or control PBS-liposomes (PBS) as schematic protocol indicated during DSS colitis induction (B). Body weight (C) and DAI (D) were monitored daily. *P < 0.05, **P < 0.01 (WT + MDP) vs (miR-155^−/− + MDP) (Student’s t-test). (E) WT (n = 12) mice were adoptive transferred intravenously with 5 million WT or miR-155^−/− BMDMs (BMDCs) as the schematic protocol indicated during DSS colitis induction. Body weight changes (F) and DAI (G) of WT mice with transferred WT or miR-155^−/− BMDMs were monitored throughout the study. **P < 0.01, (miR-155^−/− BMDM → WT) vs (WT BMDM → WT) (Student’s t-test). (H,I) Body weight changes (H) and DAI (I) of WT mice with transferred WT or miR-155^−/− BMDCs were monitored throughout the study. ns (miR-155^−/− BMDCs → WT) vs (WT BMDCs → WT) (Student’s t-test). Data are representative of two independent experiments (mean and SD). WT, wild-type. MDPs clodronate-liposomes. BMDMs, bone marrow-derived macrophages. BMDCs, bone marrow-derived dendritic cells.