Electrophysiological and Pharmacological Evaluation of Arrhythmogenic Cardiomyopathy Using Human iPSC- Derived Cardiac Tissue Models = 줄기세포 유래 심근 조직 모델을 이용한 부정맥성 심근병증의 전기생리학적 및 약물 반응 특성 연구

다국어 초록 (Multilingual Abstract)

The development of engineered cardiac tissues has substantially advanced our understanding of cardiac disease mechanisms and enhanced the predictive accuracy of therapeutic screening for cardiomyopathies. In arrhythmogenic cardiomyopathy (ACM), an inherited disorder characterized by defective intercellular adhesion and mislocalization of connexin-43 (Cx43) resulting from mutations in desmosomal proteins such as plakophilin-2 (PKP2) and plakoglobin (PKG), the alignment of cardiomyocytes plays a critical role in determining electrical propagation and therapeutic outcomes. To investigate the influence of myocardial anisotropy on ACM phenotypes, we fabricated cardiac tissue chips using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and neonatal rat ventricular myocytes (NRVMs). These cells were cultured on micromolded gelatin substrates that reproduced longitudinal, transverse, and isotropic myocardial architectures. Tissues carrying PKP2 or PKG mutations exhibited characteristic ACM features, including slowed conduction, disrupted Cx43 localization, and elevated arrhythmic susceptibility. Treatment with the glycogen synthase kinase-3β inhibitor SB216763 effectively restored Cx43 organization and conduction velocity, most prominently in longitudinally aligned tissues, whereas its efficacy was limited in transverse and isotropic constructs. These findings underscore the importance of incorporating physiological myocardial anisotropy into engineered cardiac models to faithfully recapitulate ACM pathophysiology and improve the reliability of therapeutic screening. This approach provides a promising foundation for precision medicine by enabling more accurate predictions of therapeutic efficacy and patient-specific treatment responses in ACM.

목차 (Table of Contents)

• 1. Introduction 1
• 2. Materials and methods 6
• 2.1 NRVM Cell culture 6
• 2.2 hiPSC maintenance and differentiation 7
• 2.3 Adenovirus transduction 8
• 2.4 Fabrication of micromolded substrates 9
• 2.5 Immunofluorescence staining 10
• 2.6 Optical mapping and electrical stimulation 11
• 3. Results 14
• 3.1 Tissue engineered platform to study cardiac conduction system 14
• 3.2 Longitudinally micromolded gelatin substrates promote cardiomyocyte alignment and conduction performance 15
• 3.3 Connexin-43 localization is disrupted in desmosomal mutant cells 20
• 3.4 Conduction differences and pharmacological effects are dependent on pattern geometry 23
• 4. Discussions 27
• 4.1 Role of Structural Alignment in Conduction 29
• 4.2 Wnt Pathway Activation and the Need for Anisotropy 30
• 4.3 Implications for Disease Modeling, Drug Screening and Translational Consideration 31
• 4.4 Ion Channel Contributions, Fibroblast Integration, and Advancing Translational Relevance 34
• 5. Conclusion 36
• 6. References 37
• 7. Supplement Figures 43
• 8. 국문초록 50
• 9. 감사의 글 51