Advisor(s)
Jianyi Zhang
Committee Member(s)
Hind Lal
Jianyi Zhang
Lei Ye
Manuel Rosa-Garrido
Min Xie
School
Joint Health Sciences (Interdisciplinary)
Document Type
Dissertation
Department (new version)
Biomedical Engineering
Date of Award
9-9-2024
Abstract
Cardiovascular diseases are the leading causes of global death. Due to the limit regenerative capacities of adult mammalian cardiomyocytes (CMs), myocardium is repaired with non-contractile fibrotic scar after a myocardial infarction (MI). Various strategies, including apical resection (AR) and cardiac cell therapy, are being explored to promote heart regeneration after MI. This dissertation research aimed to identify proliferating pig CM population after AR and understand the underlying mechanism of human induced pluripotent stem cells (hiPSCs) derived CMs (hiPSC-CMs) implantation for regenerating the pig hearts after MI. Our previous study showed that AR prolonged the heart regeneration window to postnatal day-28 (P28). Thus, we conducted a single-nucleus RNA sequencing (snRNA-seq) study to characterize CM populations after AR on P1 (ARP1), MI on P28 (MIP28), and ARP1 with MI on P28 (ARP1MIP28). snRNA-seq data analysis clustered ten cardiomyocyte populations (i.e. CM1-CM10). Notably, only CM1 was exclusively observed in P28 pig hearts after A/R on P1, suggesting it may retain a latent capacity for proliferation up to P28. Another way to attain heart regeneration is to repopulate fibrotic scar with exogenous CMs in the hearts after MI. To achieve this, I developed a hiPSC line with knockout of human leukocyte antigen (HLA) class-I and -II (KO) and overexpression of the cell-cycle regulatory molecule cyclin D2 (OE) under myosin heavy chain promoter (KO/OEhiPSCs). Then, KO/OEhiPSCs were differentiated into CM (KO/OEhiPSC-CMs) spheroids (KO/OESpheroids) using a suspension differentiation protocol. When intramyocardial injected into the pig hearts after ischemia/reperfusion injury, KO/OESpheroids significantly improved cardiac function, reduced scar size, and promoted pig heart regeneration. The benefits were achieved by follistatin secreted from KO/OEhiPSC-CMs, as it targeted YAP signaling to promote CM proliferation in cultured WThiPSC-CM in-vitro and in mouse CMs after MI in-vivo. Furthermore, snRNAseq data revealed a cluster of proliferating CMs with up-regulated HIPOO/YAP signaling pathway, corroborated by Western blot and immunohistology which showed significantly increased prevalence of YAP protein and nuclear YAP protein in KO/OEhiPSC-CM spheroid-treated pig hearts. Collectively, these studies demonstrated that AR promoted cardiac regeneration, while KO/OEhiPSC-CMs induced proliferation of endogenous pig CMs through secreted follistatin, thereby facilitating cardiac repair and regeneration and providing new avenues for heart regeneration.
ProQuest ID
Recommended Citation
Wei, Yuhua, "Promoting Endogenous Cardiomyocyte Proliferation In Large Mammal Hearts Via Cell Transfer Therapy Or Apical Resection: Understanding The Underlying Mechanism" (2024). All ETDs from UAB. 7614.
https://digitalcommons.library.uab.edu/etd-collection/7614
