Human Neonatal Thymus Mesenchymal Stem Cells Promote Neovascularization and Cardiac Regeneration

Figure 2

(a) Scaffoldless cell sheet made by culturing 4 × 10⁶ ntMSCs in a thermoresponsive polymer-coated 35 mm dish. (b) H&E stain of an ntMSC cell sheet demonstrates high cell density, 3D organization. Scale bar = 100 μm. (c) Cell sheet generation stimulated the expression of proangiogenic genes in ntMSCs as compared to monolayer culture. (d) Echocardiogram evaluation of untreated controls () and ntMSC cell sheet-treated RNU nude rats () that underwent left coronary ligation. Ejection fraction (EF) and fractional shortening (FS) for both groups were identical 3 days after left coronary ligation but only the ntMSC cell sheet treated animals showed significant improvement at 28 days. (e, f) Immunohistochemistry with anti-vWF antibody demonstrated that the vascular density in the peri-infarct region increased with ntMSC cell sheet treatment. White asterisks denote blood vessel lumens containing red blood cells. Scale bars = 50 μm. (g, h) Masson trichrome stain demonstrated that the postinfarct scar region (blue) was decreased by ntMSC cell sheet treatment. Scale bars = 3 mm. (i, (j) Confocal microscopy and TUNEL staining revealed decreased apoptosis in the LV myocardium of ntMSC cell sheet-treated animals. Scale bars = 50 μm.