Fig. 5.

CSCs traverse the wall of coronary vessels migrating to the myocardium. (A) Detection by two-photon microscopy of numerous EGFP^POS clonogenic CSCs (green) located within the lumen of coronary vessels (rhodamine-labeled dextran; red) 20 min after cell injection. (A–E) Transcoronary migration of EGFP^POS CSCs to the myocardium; images of the same field (A–E) were taken at 30-min intervals, starting at 30 min after the intravascular delivery of these cells. Arrowheads point to the cells that translocated through the vessel wall (C–E). Arrowheads point to the same EGFP^POS CSCs detected in the living tissue by two-photon microscopy (E, green) and after fixation, embedding, and staining of the same region of the ventricular wall by confocal microscopy (F, green). Myocytes are stained by cardiac myosin (magenta), and nuclei are labeled by DAPI (blue). Red fluorescence in the confocal microscopic image illustrates the coronary circulation (rhodamine-labeled dextran, red). (Inset) Superimposition of E and F. Two-photon microscopy: focal depth, 20 μm. Confocal microscopy: section thickness, 10 μm. (Bars, 20 μm.)