Fig 2.

Expression of elastin in the infarcted myocardium. (A) Seven days after ligation, BMSCs transduced with Ad-CMV-elastin (BMSC-elastin) or Ad-CMV-GFP (BMSC-G) were injected into the central region and border zone of the infarct. Medium alone served as control. Human and rat elastin mRNA in the infarct and border regions was evaluated by RT-PCR 7 days after injection, with primer sets specific for human and rat elastin. GAPDH served as a loading control. The BMSC-elastin group expressed human elastin mRNA, but no human elastin mRNA was found in the medium control or BMSC-G groups. Induction of the human elastin gene in transduced rat BMSCs did not alter the expression of endogenous elastin as no significant changes in rat elastin gene expression were observed among the medium control (n = 3), BMSC-G (n = 3) or BMSC-elastin (n = 5) groups. (B) Seven days after ligation, BMSCs transduced with Ad-CMV-elastin (BMSC-elastin) were injected into the infarct. Medium alone served as control. Human elastin in the infarct and border regions was evaluated by immunofluorescent staining 7 days after injection. Representative micrographs (200× magnification) show that the BMSC-elastin group expressed human elastin protein, but no human elastin was found in the medium control and BMSC-G groups. Nuclei were stained with DAPI. (C) Verhoeff Van Gieson staining of mid-papillary transverse myocardial sections (400× and 40× magnification) of infarcted myocardium shows elastin fibres in the medium control, BMSC-G and BMSC-elastin groups 9 weeks after cell transplantation. (D) The pixel area positive for elastin was significantly greater in the scar and border zone of the BMSC-elastin group compared with medium control and BMSC-G groups (n = 5 per group for the scar, n = 6 per group for the border zone) (**P < 0.01 versus control).