Annually, there are ~790,000 cases of myocardial infarction (MI) in the United States. Typically, MI progresses into heart failure where patients have a high risk of mortality within 5 years after diagnosis. While animal models provide a valuable model system of MI, interspecies differences lead to inaccurate recapitulation of human myocardium. To address this, our lab originally developed 3D human cardiac organoids through self-assembly of hPSC-CMs, human primary adult cardiac fibroblasts (adult-cFbs), endothelial cells, and stromal cells. Further, we leveraged the oxygen diffusion limitation in 3D human cardiac organoids along with chronic adrenergic stimulation to generate an organotypic model of post-MI hearts. The human cardiac infarct organoids recapitulated transcriptional, structural and functional hallmarks of post-MI myocardium. However, the use of primary, non-myocyte cell populations in our current organoids limit their potential to mimic patient-specific myocardium. To develop human isogenic cardiac organoids, we are collaborating with Dr. Sean Palecek at the University of Wisconsin-Madison to derive cardiac fibroblasts from human pluripotent stem cells (hPSC) to replace adult-cFbs in our cardiac organoid model. Dr. Palecek?s lab has developed expertise to direct hPSC differentiation into cardiac fibroblasts (hPSC-cFbs) in 2 different lineages: epicardial-derived fibroblasts (hPSC-cFb(EpiC)s) and second heart field progenitor-derived fibroblasts (hPSC- cFb(SHFP)s). While both lineages contribute to cardiac fibrosis and are functionally similar, in murine hearts, the epicardium is the predominate source of ventricular cardiac fibroblasts while a small population arise from the endocardium. In addition, the enhanced maturation may be needed for the hPSC-cFb(EpiC)s to replace human adult-cFbs, as our preliminary data that showed that prolonged culture improved cell organization of hPSC-cFb(SHFP)s in cardiac organoids when compared to that of adult-cFb organoids. The central hypothesize of this proposal is that high passage hPSC-cFb(EpiC)s will best replicate adult-cFb transcriptomics and functionality. The proposal is innovative in that, for the first time, we will identify a suitable hPSC-cFb population to replace adult-cFbs to develop an isogenic 3D organotypic model of human myocardium. Our long-term goal is to develop patient-specific cardiac organoids for in vitro disease modeling and drug testing. Accordingly, we will pursue the following two Aims: 1) Determine the effectiveness of high passage hPSC- cFb(EpiC)s to replicate the transcriptomics and functionality of adult cFbs, and 2) Determine the effectiveness of human cardiac organoids composed of high passage hPSC-cFb(EpiC)s in modeling post-MI human myocardium and responsiveness to anti-MI therapeutics. We also will perform single cell RNA-seq to examine the heterogeneity of hPSC-cFb(EpiC)s in response to our infarction protocol. Completion of this study would provide the first step towards an isogenic human myocardium model. The single cell RNA-seq studies will reveal the various roles/subpopulations of cardiac fibroblasts in post-MI human myocardium.

Public Health Relevance

Cardiovascular disease is the leading cause of death in the world. Patient-specific human cardiac organoids are a potential powerful platform for in vitro cardiovascular disease modeling. The goal of this study is to identify a suitable hPSC-derived cardiac fibroblast source for the isogenic organoid development.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
1F31HL154665-01
Application #
10067745
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Lidman, Karin Fredriksson
Project Start
2020-09-30
Project End
Budget Start
2020-09-30
Budget End
Support Year
1
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Medical University of South Carolina
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29407