Figure 3. shRNA-mediated knockdown in the heart is dose-dependent.

Fluorescent tissue sections showing GFP expression in ubc-GFP mice 7 weeks after: (A) being treated as uninjected controls (n=2) or (B)-(D) injection with 1.8×10¹⁰ (n=3), 9.0×10¹⁰ (n=3), or 1.8×10¹¹ (n=2) viral genomes per mouse, respectively. Scale bars are equal to 50 microns. (E) GFP mRNA from harvested cardiac tissue, normalized by GAPDH and expressed relative to the uninjected control group. qPCR analysis of mRNA demonstrated a 55% reduction in GFP mRNA with the medium dose of 9×10¹⁰ vg and an 82% reduction in transcript with the high dose of 1.8×10¹¹ vg compared to the control group (p=0.052).