Figure 2. Multiple organ injuries in endothelial cell-KO mice.

(A) Severe atelectasis occurred in all ADAR1^EC-KO mice that died within 3 wk of birth. Panel (A) shows the postmortem lungs of an ADAR1^EC-KO mouse and a wild-type mouse at two and a half weeks of age. The circles indicate the collapsed areas. The right lung almost completely collapsed. At, atelectasis area. (B) HE-stained lung sections of ADAR1^EC-KO mice show many alveoli were collapsed, and total air space was dramatically reduced. “At,” indicate the areas with complete atelectasis. (C) The microscopic analysis found apparent morphologic changes in multiple organs, including the lungs, liver, and intestine. On the liver sections, areas of injured and necrotic hepatocytes were scattered in the relatively normal hepatocyte areas. The injured and necrotic areas were circled and labeled with “Inj.” On the small intestine sections, villi became scarce, and the length of the villi was dramatically decreased with structure interrupted. The scale bar is 100 μm. (D) On the H-E–stained sections of the kidney and liver, the tissue structures were disrupted by the tubule-like empty spaces. CD31 antibody staining showed the tubule spaces were lined by the endothelial cells with CD31 positive staining, confirming they were dilated-blood vessels. “V,” indicates the enlarged vessel structures. Images were taken with 10× and 20× objective magnifications as indicated. Scale bars are 200 and 100 μm, respectively.