FIG. 5.

Factors secreted by AECII after irradiation can alter macrophage polarization in a 12-LOX dependent fashion. Panel A: Primary AECII cultures were generated from lung digests of wild-type (WT) or 12-LOX-deficient mice (Alox12^−/−) and in vitro irradiated (0 Gy or 17.5 Gy). Conditioned media from irradiated AECII cultures was applied to wild-type bone marrow-derived monocytes (BMDM). Panel B: IL-13 mRNA expression in AECII cultures from wild-type and Alox12^−/− mice was determined with RT-PCR. Panels C and D: BMDM from wild-type mice were treated with conditioned media from irradiated wild-type or Alox12^−/− pneumocyte cultures. After 24 h of exposure to conditioned media, RNA from macrophages was isolated and the expression of arginase-1 and iNOS was assessed. Columns are the mean and bars represent SD. *P < 0.05 for comparison to isogenic control (0 Gy) by ANOVA. **P < 0.05 for comparison to irradiated wild-type by ANOVA. Panels E and F: BMDM from wild-type and Alox12^−/−mice were treated with vehicle, LPS, IL-13 or 12S-HETE. After 24 h of exposure, RNA from macrophages was isolated and the expression of arginase-1 and iNOS was assessed. Columns are the mean and bars represent SD. *P < 0.05 for the comparison to wild-type vehicle by ANOVA. **P < 0.05 for the comparison to wild-type within each treatment group by ANOVA. ***P < 0.05 for the comparison to Alox12^−/− within a treatment group by ANOVA.