The role of miR-34b-5p in bone marrow derived macrophage polarization

Abstract

Objective To investigate the role of miR-34b-5p in the polarization of bone marrow derived macrophages(BMDM). Methods Bone marrow cells were separated from mice, which were induced by macrophage colony-stimulating factor (M-CSF) to differentiate into BMDM.BMDM were stimulated by control treatments (PBS), M1 [ lipopolysaccharide ( LPS) and interferon (IFN)-γ] or M2[(interleukin, IL)-4] polarization stimulus, respectively for 24 h. Real-time quantitative PCR was used to detect miR-34b-5p expression of BMDM.BMDM were transfected with miR-34b-5p mimic, negative control mimic (NC mimic), miR-34b-5p inhibitor, and negative control inhibitor (NC inhibitor). After 24 h, BMDM were treated with control or polarization stimulus, real-time quantitative PCR, flow cytometry and enzyme linked immunosorbent assay (ELISA) were used to detect the expression of inducible nitric oxide synthase (iNOS), TNF-α and IL-6. Results Compared with control group, the expression of miR-34b-5p was elevated in M1 BMDM(P 0.05). Compared to the cells treated with control mimic, over-expressed miR-34b-5p increased the expression of iNOS, TNF-α and IL-6 in M1 and M2 BMDM and control cells(P 0.05), while over-expressed miR-34b-5p increased the expression of iNOS, TNF-α, and IL-6 the corresponding cells(P<0.05). Conclusion The expression of miR-34b-5p in M1 BMDM is elevated.miR-34b-5p promotes M1 polarization of BMDM. Key words: miR-34b-5p; Bone marrow derived macrophages; Innate immune response; Inducible nitric-oxide synthase; Tumor Necrosis factor-α; Interleukin-6