Figure 1: Specific targeting of Tert to the heart.

(a) Anti-eGFP immunohistochemistry to assess tropism of AAV9-eGFP viruses to the myocardium. Different concentrations of viruses are indicated. Scale bars, 1,000 μm (top row); (200 μm) in higher magnification images. (b) Tropism at the indicated AAV9-eGFP viral concentration to the liver and brain. Scale bars, 1,000 μm (top row); 200 μm (bottom row). Black arrows indicate eGFP-positive cells. (c) Percentage of viral transduction in the indicated tissues. (d) AAV9 specifically transduces cardiomyocytes. Co-immunostaining of LV tissue section was done with anti-myosin heavy chain (MHC) to stain cardiomyocytes (red) and with anti-eGFP (green) antibodies to identify infected cardiomyocytes. Cell nuclei were stained with DAPI (blue). Scale bar, 50 μm. (e) Percentage of eGFP-positive (AAV9 infected) cardiomyocytes or cardiac fibroblasts. (f) Fold changes in mRNA levels of Tert after injection of different AAV9-Tert doses in the heart and liver relative to non-injected animals (no virus). (g) Telomerase activity in extracts of sham and MI hearts infected with AAV9-empty or AAV9-Tert was determined following the telomeric repeat amplification protocol (TRAP). All graphs show mean values, error bars indicate s.e.m, n=number of mice. Two-sided Student’s t-test was used for statistical analysis and P-values are shown.