Fig. 2
Myeloid DNMT3B inhibits alternative macrophage polarization in the lungs during bleomycin-induced pulmonary fibrosis. A Total cell numbers in bronchoalveolar lavage fluid (BALF) of control (Dnmt3bfl/fl) and DNMT3B conditional knockout (Dnmt3bfl/flLysMcre) mice 21 days after saline of bleomycin treatment. B Percentage of classical alveolar macrophages (Siglec Fhi AMs) and alternative alveolar macrophage populations (CD11bhi AMs) in BALF of control (Dnmt3bfl/fl) and DNMT3B conditional knockout (Dnmt3bfl/flLysMcre) mice 21 days after saline or bleomycin treatment analyzed by flow cytometry. C Relative gene expression of alternative macrophage markers Arg1 (Arginase 1), Fizz1 (Resistin like alpha), Spp1 (Secreted Phosphoprotein 1), Pdgfa (platelet derived growth factor subunit A), Mmp8 (matrix metalloproteinase 8) and Mmp12 (matrix metalloproteinase 12) in BALF cells of control (Dnmt3bfl/fl) and DNMT3B conditional knockout (Dnmt3bfl/flLysMcre) mice 21 days after saline or bleomycin treatment determined by RT-qPCR. Expression levels are relative to Hprt (hypoxanthine–guanine phosphoribosyltransferase). D Percentage of DNA methylation at region p1 and p2 of the Arg1 promoter in control (Dnmt3bfl/fl) and DNMT3B conditional knockout (Dnmt3bfl/flLysMcre) bone marrow-derived macrophages (BMDMs) 0, 6 and 24 h after IL4 (20 ng/ml) stimulation. Data are presented as mean ± SEM, n = 10 mice per group (bleomycin treated) or 4 mice per group (saline control) in A, B; n = 6 in C. Black bars: littermate control mice, open bars: myeloid specific DNMT3B deficient mice. *p < 0.05, **p < 0.01, ***p < 0.001