Ccn5 Gene Therapy Reduces Myocardial Infarction Size and Improves Contractility in Ischemic Cardiomyopathy

Abstract

Introduction: Salvaging ischemic myocardium post acute myocardial (MI) infarction has not been achieved with current treatments. Gene therapy via adeno-associated virus (AAV) offers a promising strategy since myocytes can be reprogrammed fast after MI. CCN5 is a pleiotropic target shown to rescue function and reduce fibrosis in murine models. CCN5’s mode of action is 2 fold: upregulating survival and reducing fibrosis mechanisms. Here, we attempt to validate CCN5 in a sheep MI model. Hypothesis: CCN5 will salvage post MI myocardium and improve extracellular matrix composition through reducing levels of: TGFB signalling, myofibroblasts and collagen I deposition. Methods: Surgical ligation of 2 arteries was performed in n=12 sheep and randomized between AAV9 null or AAV9 CCN5. 30 min after MI, 15 single AAV injections were given in the MI area, total 1 x 1013. MRI assessed function at 1 and 3 months. Assays: QPCR of genome copies, CCN5 expression, TGFB ELISA, collagen I and histology. Results: CCN5 reduced MI size to [7±2%] F1A as compared with nulls F1B [18±2%] at 3 months. LV Ejection fraction was preserved with CCN5 [50±4%] compared to heart failure in the nulls [36±3%] F1C. End Systolic volumes were higher in the nulls [84±6mL] in to CCN5 [52±4mL] F1D. QPCR of AAV.CCN5 detected 995086 GC per 1 ug DNA or 8.1 GC/cell in the injected zones, but not distal areas. Cardiac specific CCN5 expression confirmed via confocal Fig1E and western blot. TGFB levels were significantly less in CCN5 treated samples [0.67±0.2AU] to nulls’s areas [1.6±0.3AU]. FACS cell sorting revealed significantly less myofibroblast detection range 0.2-4% for CCN5 samples versus >20% for nulls Fig1F. Collagen I (red) stain revealed significantly less formation in CCN5 [3.3±0.05AU] F1G vs high [8.2±0.07AU] in nulls F1H. Conclusions: CCN5 preserves myocytes in the setting of MI and reduces chronic fibrosis markers. CCN5 gene therapy could be a treatment option for early stage MI or cardiac surgery indications.