Detection of CM-DiI⁺/MPIO⁺ human ATMSCs in the pre-immune fetal sheep myocardium via immunohistochemistry.

<p>Exemplary image series post intramyocardial transplantation of human ATMSCs into the fetal myocardium. Morphologically CM-DiI⁺/MPIO⁺ human ATMSCs could be easily identified within the fetal heart tissue suggesting to be in good shape and viable. The cells appeared to be integrated within the fetal myocardium and could be found as clusters as well as in the interstitial and intravascular spaces (<b>A–I</b>; <i>black arrows</i>). The cells stained positive for human specific Major Histo Compatibility Complex 1 (MHC-1) clearly confirming the human origin (<b>A and B</b>; <i>black arrows</i>) and also stained positive for anti-FITC detecting the Dragon Green fluorochrome labelled MPIOs within the human cells (<b>C and D</b>; <i>black arrows</i>). In addition, double staining for ALU Sequence and anti-FITC further confirmed the presence of the injected CM-DiI⁺/MPIO⁺ human ATMSCs within healthy heart tissue (<b>E and F</b>; <i>black arrows</i>) as well as in infarcted myocardium (<b>G–I</b>; <i>black arrows) Scale Bar: 100 um (A–C, E, G, H), 50 um (D, F, I)</i>.