FoxC1-Induced Vascular Niche Improves Survival and Myocardial Repair of Mesenchymal Stem Cells in Infarcted Hearts

Figure 6

FoxC1 is required for survival and neovascularization of transplanted MSCs. MSCs were infected with a reporter retrovirus expressing EGFP before transplantation and were recognized as EGFP-positive cells. (a–c) FACS assessment of the (a) percentages of EGFP-positive cells (EGFP⁺) relative to the whole ventricular cell population and the number of EGFP⁺MSCs present in the IHs after 30 days of transplantation; (b) percentages of Ki67 (proliferation index marker) and EGFP double-positive cells (Ki67⁺EGFP⁺) relative to the whole EGFP⁺ population, factor VIII and EGFP double-positive cells (factor VIII⁺EGFP⁺) relative to the whole EGFP⁺ population (c), or myosin heavy chain (MHC) and EGFP double-positive cells (MHC⁺EGFP⁺) relative to the whole EGFP⁺ population (d) as assessed by FACS. Three images in the left row represent the representative phenotypes of gated (a) EGFP⁺ in total cardiomyocytes, (b) Ki67⁺EGFP⁺, (c) MHC⁺EGFP⁺ cells, and (d) factor VIII⁺EGFP⁺ cells evaluated by FACS in transplanted MSCs. The image in the far right row represents the statistical results of FACS. All graphical data are the . vs. MSC-treated CON IHs, ^† vs. MSC-treated adFoxC1 IHs ( per group). (e–g) Immunofluorescence staining showing that transplanted cells expressed Ki67 (e), factor VIII (f), and MHC (g). The transplanted cells were prelabeled with EGFP (green); the nuclei were stained with DAPI (blue). Ki67 (red) was mainly expressed in the nuclei and the nuclear membrane. . The cytoplasm was stained with anti-factor VIII antibody (red). The myocardium was stained with anti-MHC antibody (red). . Engrafted EGFP-prelabeled cells expressing Ki67, factor VIII, or MHC were the most numerous in the adFoxC1 IHs and were lowest in siFoxC1-transfected IHs (arrows).