3D Bioprinted Human Model of Duchenne Muscular Dystrophy (DMD) Cardiomyopathy to Study Disease Progression with Imposed Force and Precise Gene Editing

点击翻译按钮获取中文摘要

Duchenne muscular dystrophy (DMD) cardiomyopathy is ubiquitous, deadly, and results from mutations in the dystrophin gene. Dystrophin is an essential component of cardiac mechanotransduction (MT) and distributes mechanical stress across the sarcolemma. In DMD, the absence of dystrophin results in cardiomyocytes that are vulnerable to contraction-induced damage, which accelerates disease progression. Our understanding of the early progression of DMD cardiomyopathy is limited due to models that do not fully recapitulate human disease, thus limiting development of effective therapies. Given the essential role of dystrophin in connecting the contractile apparatus to the extracellular matrix (ECM) for MT, it is critical to augment DMD cardiomyopathy models to include cell-ECM engagement with applied physiological force to recapitulate early changes at the organ level necessary to test novel therapies. The human chambered muscle pump (hChaMP) can do just that. The hChaMP is generated by 3D printing human induced pluripotent stem cells and bio-ink to yield a pump that can be pressurized to impose progressive strain. The long-term goal is to determine mechanisms by which DMD cardiomyopathy progresses to develop novel disease specific therapies to prevent cardiomyopathy. The overall objective is to assess the role of altered MT and ECM dynamics in the absence of dystrophin on DMD cardiomyopathy disease progression and to test dystrophin gene editing in a DMD hChaMP with volumetric loading. The central hypothesis is that the loss of dystrophin leads to increased vulnerability to mechanical stress resulting in early altered cardiac MT and ECM dynamics that promote disease progression and that early dystrophin replacement will limit contraction-induced injury by restoring MT and ECM homeostasis and thereby rescue DMD cardiomyopathy. Our central hypothesis will be tested in two specific aims: 1) To evaluate the impact of altered MT on DMD cardiomyopathy disease progression using the hChaMP model system with progressive volumetric loading; 2) To determine the impact of dystrophin restoration with DMD precise gene editing on cardiac remodeling mechanisms dictating disease progression in DMD cardiomyopathy. In aim 1, we will generate a DMD hChaMPs to assess the physiologic impact of increased volumetric pressure on the human DMD phenotype early and later. In aim 2, we will introduce DMD precise gene editing to restore dystrophin both early and late in DMD hChaMPs with volumetric loading and assess the physiologic and transcriptional changes. At the successful completion of the proposed research, the expected outcomes of our study is the characterization of early DMD cardiomyopathy progression with loading and the underlying molecular mechanisms. The proposed research is innovative as it combines enabling technologies to develop a 3D preclinical model of human DMD cardiomyopathy that mimics disease progression and correction with precise gene editing. These findings will have a significant impact on human health by increasing our understanding of disease progression and a strong basis for treating and preventing DMD cardiomyopathy.