Vascular remodeling induced by CD133⁺ cells. Organs were harvested from CD133⁺-engrafted mice and fixed in formalin. A pathologist blinded to study groups analyzed paraffin-embedded tissue sections after specific stainings. (A) H&E staining of lungs from a control CD133⁺-engrafted mouse. (B-C) H&E staining of lungs from a PAH CD133⁺-engrafted mouse (B); arrows indicate in situ thrombi and recent thrombi (C). (D-E) Human PAH lung. Low- and high-power images of occlusion of tufts of capillaries in plexiform lesion by recent thrombi (arrows). (F-H) Lung endothelial cell damage in PAH CD133⁺-engrafted mice, H&E and α smooth muscle staining, respectively. (G) High-power field of the boxed region in panel D. (I-J) Lung PAH CD133⁺-engrafted mouse, organized thrombus in large vessel with recanalization (Masson trichrome). (J) High power of the boxed region in panel I. (K) H&E staining of heart from control CD133⁺-engrafted mouse. (L-M) H&E staining of heart from PAH CD133⁺-engrafted mouse, thrombi in the right ventricle with infarction and ischemia. (N) H&E staining of kidney from PAH CD133⁺-engrafted mouse. Arrows indicate in situ thrombi. (O-R) Lung α smooth muscle actin staining, blood vessels with muscle indicated by arrows. Scale bars indicate 100 μm.