Search bioRxiv⌕ Search

bioRxiv · 10.1101/2023.10.02.560452

Gene Therapy for Cardiomyopathy associated with Duchenne Muscular Dystrophy in a Pig Model

Abstract

BackgroundGenetic cardiomyopathies caused by mutations in the dystrophin gene (DMD) are only partially responsive to current pharmacological heart failure treatments, although dilated and arrhythomogenic phenotypes of cardiomyopathy are frequent. ObjectiveIn this study, we tested whether a normalization of Ca2+-handling by forced expression of SERCA2a in cardiomyocytes mitigates heart failure and arrhythmogenesis in a pig model for Duchenne muscular dystrophy (DMD). Methods and resultsMale offspring of pigs lacking DMD exon 52 are characterized by heart failure with reduced ejection fraction (HFrEF, EF 34.5{+/-}1.8% vs. 49.2{+/-}1.0% in control hearts), arrhythmogenesis due to large apical regions of reduced voltage amplitude and sudden cardiac death with a lifespan of usually less than 4 months. Slow antegrade intracoronary infusion of AAV1.SERCA2a (3x1013 virus genomes (vg) per pig) improved left ventricular ejection fraction (EF 47.3{+/-}2.0%, p<0.05) to a similar extent as germline editing of DMD{Delta}52 to DMD{Delta}51-52, inducing a Becker dystrophy (BMD) genotype (EF 46.7{+/-}3.8%). Moreover, AAV.SERCA2a significantly reduced myocardial inflammation and fibrosis and areas of reduced AP amplitude. ConclusionsIn DMD pigs, 3x1013vg/heart of GMP-grade AAV1.SERCA2a sufficed to normalize left ventricular function and improved electrical vulnerability of the heart. Hence, AAV.SERCA2a may serve as a treatment option for DMD cardiomyopathy.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Baehr, A., Hoppmann, P., Bozoglu, T., Stirm, M., Luksch, I., Ziegler, T., Hornaschewitz, N., Shresta, S., Shashikadze, B., Stöckl, J. B., Raad, N., Blum, H., Krebs, S., Fröhlich, T., Baumgartner, C., Nowak-Imialek, M., Walter, M., Weber, C., Engelhardt, S., Moretti, A., Klymiuk, N., Wurst, W., Laugwitz, K. L., Hajjar, R. J., Wolf, E., Kupatt, C.. 2023-10-03. Gene Therapy for Cardiomyopathy associated with Duchenne Muscular Dystrophy in a Pig Model. https://doi.org/10.1101/2023.10.02.560452

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Hypothalamic Farnesoid X Receptor deficiency alters energy balance by modulating hepatic glucose production and adipose tissue metabolism through central insulin signaling.

Objectives: The bile acid nuclear receptor Farnesoid X Receptor (FXR, NR1H4) is a major regulator of metabolism and energy homeostasis in peripheral organs. It modulates bile acid, glucose, and lipid metabolism, as well as fat mass and body weight. However, FXR is also expressed in the brain, particularly in the hypothalamus, a key center for the regulation of energy homeostasis. Although one study has demonstrated a role for brain FXR activation in energy balance, its specific hypothalamic role is still unknown. Here, we examined the role of FXR in the mediobasal hypothalamus in the regulation of energy balance. Methods: We used a genetic approach combined with metabolic phenotyping to determine the effect of FXR invalidation in the mediobasal hypothalamus on metabolic parameters involved in the central regulation of energy homeostasis. Results: Our results demonstrate that hypothalamic FXR deficiency induces a positive energy balance, resulting in a reduction in energy expenditure due to alterations in glucose metabolism accompanied by structural changes in white adipose tissues. Conclusion: This study uncovers a previously unrecognized role for hypothalamic FXR in the central homeostatic control of energy balance, providing new insights into its contribution to peripheral glucose metabolism and adipose tissue structural remodeling.

physiology↗

Rad and Phospholamban are Key Drivers of the Ventricular Adrenergic Response and Stress-Induced Arrhythmia

The adrenergic response is a fundamental mechanism that regulates heart rate (chronotropy), cardiac contractility (inotropy) and relaxation (lusitropy). Adrenergic stress is also a recognized trigger of arrhythmia in disease. Yet, our understanding of the underlying molecular basis remains incomplete. Protein kinase A (PKA) and the calcium/calmodulin-dependent kinase II (CaMKII) phosphorylate multiple targets proposed to participate in the adrenergic response, including the GTP-binding protein Rad, phospholamban (PLB) and ryanodine receptor 2 (RyR2). Here we demonstrate that phosphorylation of both Rad and PLB is necessary for inotropy and lusitropy. We show that changes in cardiac contractility and relaxation are primarily dependent on intracellular calcium handling. Finally, we report that Rad and PLB control stress-induced arrhythmogenesis, despite the phosphorylation of other pro-arrhythmic targets. We have identified the essential molecular components of the adrenergic response, resolving a long-standing debate in cardiac excitation-contraction coupling and refining current models of sympathetic regulation in health and disease.

physiology↗

Light-cycle time-restricted feeding remodels a hidden layer of the cardiac transcriptome through sex-specific transcript switching

Light-cycle time-restricted feeding disrupts daily cardiovascular and thermoregulatory rhythms, but the molecular effects of light-cycle time-restricted feeding on the heart have been measured only at the level of total gene expression. We used Oxford Nanopore long-read RNA sequencing to resolve the full-length ventricular transcriptome from male and female mice under ad libitum feeding or light-cycle time-restricted feeding across the 24-hour cycle. Greater than 20% of cardiac transcripts represent unannotated variants of known genes absent from the current GENCODE reference annotation. Light-cycle time-restricted feeding reorganizes transcript usage across hundreds of genes, including genes encoding splicing regulators, largely without changing total gene expression. The genes affected are sex-specific, with fewer than 2% of changes shared at the gene, transcript, and transcript-usage levels. We show that transcript-level regulation is a previously underrecognized component of the cardiac response to altered feeding behavior, undetected by conventional short-read approaches.

physiology↗