Sustained Whole-Body Functional Rescue in Congestive Heart Failure and Muscular Dystrophy Hamsters by Systemic Gene Transfer

Abstract

Background-The success of muscular dystrophy gene therapy requires widespread and stable gene delivery with minimal invasiveness. Here, we investigated the therapeutic effect of systemic delivery of adeno-associated virus (AAV) vectors carrying human ␦-sarcoglycan (␦-SG) gene in TO-2 hamsters, a congestive heart failure and muscular dystrophy model with a ␦-SG gene mutation. Methods and Results-A single injection of double-stranded AAV serotype 8 vector carrying human ␦-SG gene without the need of any physical or pharmaceutical interventions achieved nearly complete gene transfer and tissue-specific expression in the heart and skeletal muscles of the diseased hamsters. Broad and sustained (Ͼ12 months) restoration of the missing ␦-SG gene in the TO-2 hamsters corrected muscle cell membrane leakiness throughout the body and normalized serum creatine kinase levels (a 50-to 100-fold drop). Histological examination revealed minimal or the absence of central nucleation, fibrosis, and calcification in the skeletal muscle and heart. Whole-body functional analysis such as treadmill running showed dramatic improvement, similar to the wild-type F1B hamsters. Furthermore, cardiac functional studies with echocardiography revealed significantly increased percent fractional shortening and decreased left ventricular end-diastolic and end-systolic dimensions in the treated TO-2 hamsters. The survival time of the animals was also dramatically extended. Conclusions-Systemic

Construction and analysis of compact muscle-specific promoters for AAV vectors

“…26,27 Our own effort here also identified a hybrid muscle-specific synthetic promoter, in which a modified MCK enhancer was fused with an original synthetic muscle promoter (C5-12). 33 This 520 bp hybrid promoter (E-Syn) is 2-3 stronger than the original C5-12 promoter. The E-syn is active not only in the heart and diaphragm but also in other skeletal muscles without apparent myofiber-type preference, suitable for gene therapy intended for both muscle and heart.…”

“…33 This promoter was active in both heart and skeletal muscles, including the diaphragm, throughout the body. However, we did not investigate if it also displays myofiber-type preference.…”

“…The muscle-specific synthetic promoter C5-12 (Syn, 312-bp) 33 was used to drive human dystrophin genes as we described in previous studies. 15 In addition, a hybrid muscle-specific synthetic promoter (E-syn) was generated by ligation of a 2RS5 enhancer to C5-12 promoter, and it was named E-Syn promoter.…”

Heart-targeted adeno-associated viral vectors selected by in vivo biopanning of a random viral display peptide library

“…49 The efficient cardiac gene transfer in a model of dilated cardiomyopathy also emphasizes the therapeutic relevance of our approach, as it has been shown that AAV-mediated reconstitution of d-sarcoglycan AAV targeting Y Ying et al in d-sarcoglycan-deficient TO-2 hamsters can extend the lifespan of these animals by preventing heart failure. 50 Similar approaches for targeted gene transfer as described here may be used not only for therapeutic applications, but also for fundamental analysis of gene function in animal models.…”

Myocarditis following adeno-associated viral gene expression of human soluble TNF receptor (TNFRII-Fc) in baboon hearts

“…11 Cardiac expression of potentially therapeutic proteins through virally mediated gene transfer into the myocardium is a potential strategy for the treatment of heart disease. 12,13 Benefits of this approach over recurrent therapeutic interventions may include locally higher levels of protein expression, fewer systemic side effects and long-term myocardial expression of the desired protein when using vectors such as adeno-associated viruses (AAV). However, the potential adverse effects of the viral vector or the cardiac-expressed proteins that they encode remain incompletely understood.…”