Advisory Committee Chair
Jianyi Zhang
Advisory Committee Members
Margaret Xiaoguang Lui
Glenn Rowe
Adam Wende
Yang Zhou
Document Type
Dissertation
Date of Award
2021
Degree Name by School
Doctor of Philosophy (PhD) School of Engineering
Abstract
Cardiovascular disease, till now, is still the leading cause of death in the United States. As a consequences of heart attack event, cardiomyocytes death is an irreversible process accompanied with scar formation and loss of heart function. As mammalian cardiomyocytes exit cell cycle shortly after birth, with no replacement of the necrotic cardiomyocytes, the damages caused by heart attack often progress into more severe symptoms such as heart failure. To replenish damaged cardiomyocytes (CMs), many therapies, such as differentiate the induced pluripotent stem cells (iPSCs) into cardiomyocytes and direct reprogram fibroblasts into CMs, have been developed. During this dissertation study, we focused on de novo generation of cardiomyocytes using both iPSC differentiation and direct reprogramming with higher efficiency and more matured functions for regenerative medicine purpose. First of all, by deciphering the underlying mechanism of Wnt signaling pathway activation in regulating iPSCs differentiation in a temporal manner, we proposed and optimized the differentiation process and provided guidelines to consistently produce high-yield and high-quality iPSC derived cardiomyocytes. With the specific two-phase modulation of Wnt during differentiation, the yield of cardiomyocytes reached more than 90% in both monolayer and suspension culture. To approach this issue from a different perspective, we also evaluated CMs directly induced from non-myocytes by overexpressing reprogramming factors. We first ii identified EZH2 as an important epigenetic barrier during human direct reprogramming. Removal of EZH2 during direct reprogramming process leads to robust activation of cardiac genes and reduction in H3K27me3 occupancy. Furthermore, supplementing TBX20 in the current reprogramming cocktails significantly increased sarcomere and ion channel genes expression, suggesting that overexpressing TBX20 potentially generated more functional capable and matured human induced cardiomyocytes (hiCMs). The study of de novo generation of cardiomyocytes from either iPSCs or non-myocytes such as fibroblasts would provide novel insights in future personalized regenerative medicine treatment of heart failure patients.
Recommended Citation
Tang, Yawen, "De Novo Generation of Cardiomyocytes for Regenerative Medicine Treatment" (2021). All ETDs from UAB. 626.
https://digitalcommons.library.uab.edu/etd-collection/626