Integration and interaction of cardiac progenitor cells with human failing myocardium

Sun, Zhengwu (2025): Integration and interaction of cardiac progenitor cells with human failing myocardium: an ex-vivo study modeling regenerative therapy in long-term tissue culture. Dissertation, LMU München: Medizinische Fakultät

Abstract

Background: Regenerative therapy is currently getting attention as one of the most promising treatments for heart failure. However, the survival and quality of integration of stem cell-derived cardiomyocytes with human failing myocardium is still unclear. Human cardiac progenitor cells (CPCs) have the potential to differentiate into ventricular myocytes, and their engraftment in the human fail-ing myocardium may contribute to the enhancement of myocardial contractility and improve myocardial plasticity. Methods: CPCs were derived from embryonic stem cells with a cardiac directed differentiation protocol and were purified with magnetic-activated cell sorting (MACS) to remove potentially remaining undifferentiated stem cells. Human myocardium was acquired from explanted hearts of transplant recipients, and was cultured as living thin slices under biomimetic conditions, enabling con-tinuous stimulation and force measurements. CPCs were seeded on the sur-face of myocardial slices and were cocultured for 5 weeks. Real-time contrac-tility was monitored and cardiac functional assessments were performed daily. Morphological maturation and integration of CPCs were characterized by no-stain labeling (eGFP and second-harmonic generation) and immunohistology. Cell-to-cell interaction and CPCs maturation in cocultured myocardial slices were investigated by single-nucleus RNA sequencing. Results: After 5 weeks of coculture, we observed that CPCs have autonomous-ly migrated, and were uniformly distributed into deep layers of the myocardium. They expressed morphological characteristics of cardiomyocytes (elongated and t-tubule-like structure, α-actinin positive myofibrils) during coculture. Tis-sue connective proteins (connexin-43 and N-cadherin) have been formed be-tween CPC-derived cardiomyocytes and host failing cardiomyocytes. In com-parison to plain myocardial slices, functional changes were detected in cocul-ture, including enhanced force development, synchronized kinetics of contrac-tion and intracellular calcium, more positive response to rapid pacing, and tight electrical coupling. Single-nucleus RNA sequencing demonstrates dedifferen-tiation-redifferentiation of host failing cardiomyocytes and advanced matura-tion of CPC-derived cardiomyocytes during coculture. Cell-cell communication and interaction were identified between CPC-derived and host failing cardio-myocytes, which are associated with improved contractility and cardiac devel-opment of the failing cardiomyocytes in coculture. Conclusion: CPCs differentiate into cardiomyocytes and self-integrate with human failing myocardium during long-term coculture. Integration promotes contractility and affects excitation-contraction coupling. Moreover, cross-talk between CPCs and host failing myocardium develops, leading to mutual adap-tation and functional synchronization.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: Heart Failure, Cardiac Progenitor Cells, Regenerative Therapy
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften ; 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Fakultäten: Medizinische Fakultät
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 21. März 2025
• 1. Bericht­erstatter:in: Dendorfer, Andreas