A patient-specific engineered tissue model of BAG3-mediated cardiomyopathy
Summary
Pathogenic mutations in Bcl2-associated athanogene 3 (BAG3) cause genetic dilated cardiomyopathy (DCM), a disease characterized by ventricular dilation, systolic dysfunction, and fibrosis. Previous studies have demonstrated that BAG3 mediates sarcomeric protein turnover through chaperone-assisted selective autophagy to maintain sarcomere integrity in the human heart. Although mouse models provide valuable insights into whole-organism effects of BAG3 knockout or pathogenic variants, their utility is limited by species-specific differences in pathophysiology, which often do not translate to humans and contribute to the failure of clinical trials. As a result, the development of induced pluripotent stem cell-derived cardiomyocytes (iCM) and engineered heart tissues presents a promising alternative for studying adult-onset cardiac diseases. Here, we used genome engineering to generate an isogenic pseudo-wild-type control cell line from a patient-derived iPSC line carrying a pathogenic BAG3 variant, clinically presenting with DCM. While monolayer iCMs recapitulated some features of BAG3-mediated DCM, such as reduced autophagy, mitochondrial membrane potential, and decreased HSPB8 stability, they failed to develop the age-associated impairment in sarcomere integrity. Therefore, we developed a mature, patient-specific, human engineered heart tissue model of BAG3-mediated DCM and compared it to its isogenic healthy control. We demonstrated successful recapitulation of adult-like features of the clinically observed disorganized sarcomeres and impaired tissue contractility, thereby providing a platform to investigate BAG3-related pathophysiology and therapeutic interventions. © The Author(s) 2025.
| Authors | Morsink MAJ, Wang BZ, Watkins JM, Zhuang RZ, Zhang X, Chesnais F, Chen C, Lock RI, Fine BM, Vunjak-Novakovic G |
|---|---|
| Journal | Journal of tissue engineering |
| Publication Date | 2025 Jan-Dec;16:20417314251371296 |
| PubMed | 40995491 |
| PubMed Central | PMC12454951 |
| DOI | 10.1177/20417314251371296 |