Figure 3.

MIF antagonizes CS-induced endothelial cell (EC) double-stranded DNA breaks (DSBs) in vivo. Lungs from Mif^+/+ and Mif^−/− animals exposed to filtered air or CS for 0.5 months were harvested and sectioned for immunohistochemistry (A and C). MIF-deficient mice exposed to CS demonstrated a significant increase in γH2AX-positive parenchymal cells relative to air-exposed Mif^−/− and CS-challenged Mif^+/+ mice (A and B). Mif^−/− mice had significantly higher γH2AX-positive (green) ECs as detected by colocalization of isolectin staining (red) (C and D). Area of magnification denoted with dashed lines (C). Arrow identifies double positive cells, * identifies H2AX positive/isolectin negative cells. n = 5 per arm. Values are expressed as means ± SEM. A.U., arbitrary unit; IB, immunoblot.