Figure 1: rAAV9-BAG3 Improves LV Function in Mice With LV Dysfunction Secondary to Ligation of the Left Coronary Artery

(A) Western blot analysis of tissue obtained on various days from mice after retro-orbital injection of myc-tagged adeno-associated virus serotype 9 expressing BAG3 (rAAV9-BAG3). (B) Eight-week-old C57BL/6J were subjected to ligation of the left coronary artery (myocardial infarction [MI]) or sham surgery (Sham) (week 0, arrow A). The first 1 week post-surgical echocardiogram is indicated by arrow B. At 8 weeks post-surgery (arrow C), the MI and Sham groups were randomly assigned to receive 60 to 80 μl of either rAAV9-GFP (3.1 × 1012 genome copies [GC]/ml; Sham- or MI-GFP) or rAAV9-BAG3 (5 to 6.5 × 1013 GC/ml; Sham- or MI-BAG3) by injection into the retro-orbital venous plexus. Serial echocardiography was performed to determine the ejection fraction (EF), including 1 week before and 9 days and 3 weeks (arrow D) after injection. Data was analyzed using a 2-way analysis of variance for repeated measures. n = 14 Sham-GFP, n = 12 Sham-BAG3, n = 12 MI-GFP, and n = 13 MI-BAG3. ∗MI-GFP versus -BAG3 at week 9, p < 0.0001; †MI-GFP versus -BAG3 at week 11, p < 0.0001. There was no statistical difference between Sham-GFP and -BAG3 at any time points. (C) Western blot analysis of BAG3 levels in right ventricles of MI-GFP, MI-BAG3, and Sham-GFP mice (n = 3) sacrificed 11 weeks post-MI (3 weeks post-injection of rAAV9-BAG3 or -GFP) ∗p < 0.04; MI-GFP compared with MI-BAG3 or Sham-GFP. Confocal images demonstrating normal BAG3 levels in Sham-GFP hearts (D) reduced BAG3 levels in MI-GFP myocytes (E) and reconstitution and correct targeting of exogenous BAG3 in MI-BAG3 myocytes (F).