Pluripotent human stem cells, such as embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs), offer the prospect to regenerate myocardium after an infarct. To date, however, cell transplantation studies have yielded only small grafts of human cardiac muscle. Recent studies in our group and elsewhere indicate that the inclusion of stromal and vascular cells, along with cardiomyocytes, is much more effective in generating new myocardium. By transplanting pre-vascularized, engineered human myocardium, we have generated myocardial grafts that are as thick as the infarcted wall. The current proposal builds on these observations, using human cardiovascular progenitors and differentiated cells in hydrogel-based tissue engineering, to more fully regenerate the heart.
In Aim 1 we will test the ability of cardiovascular mesodermal progenitors to give rise to new myocardium in vitro and to repair the infarcted rat heart in vivo. The progenitors will be compared to """"""""tri-cell"""""""" constructs containing hESC-derived cardiomyocytes, endothelial cells and MSCs. We hypothesize that the mesodermal progenitors will have enhanced proliferative capacity and the ability to differentiate according to environmental cues, resulting in larger grafts with greater vascular density and better integration with the host.
Aim 2 tests the responses of engineered human heart tissues to conditioning regimens of cyclic strain, electrical pacing, and varying the stiffness of their hydrogel matrix. The effects on tissue structure and electromechanical function will be assessed in vitro, and optimally conditioned constructs will be compared with unconditioned constructs for their ability to repair the infarcted heart. We also will use diffusion tensor MRI to determine if pre-aligning cardiac fibers in tissue constructs influences final fiber orientation after transplantation in the heart. These experiments will be the first to study responses of ex vivo human myocardium to changes in mechanical load or rate, and thus should provide a useful system for basic science and therapeutic screens.
In Aim 3, our optimized tissue engineering approach will be compared head- to-head vs. cell therapy, to determine which offers more promise for cardiac regeneration and restoration of ventricular function. In addition to providing important pre-clinical therapeutic information, these experiments will offer insights into fundamental aspects of human cardiovascular development.

Public Health Relevance

Much of the impact that heart disease has on society results from the heart's inability to regenerate new muscle after injury. Here we propose to use adult, embryonic and reprogrammed human stem cells to create new human heart muscle in vitro and to transplant it in vivo in animal models of heart disease. These experiments will advance our understanding of human heart development and make clinical trials of heart regeneration more feasible.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL084642-05
Application #
8103550
Study Section
Myocardial Ischemia and Metabolism Study Section (MIM)
Program Officer
Liang, Isabella Y
Project Start
2006-04-01
Project End
2015-03-31
Budget Start
2011-04-01
Budget End
2012-03-31
Support Year
5
Fiscal Year
2011
Total Cost
$655,919
Indirect Cost
Name
University of Washington
Department
Pathology
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Palpant, Nathan J; Pabon, Lil; Friedman, Clayton E et al. (2017) Generating high-purity cardiac and endothelial derivatives from patterned mesoderm using human pluripotent stem cells. Nat Protoc 12:15-31
Kadota, Shin; Pabon, Lil; Reinecke, Hans et al. (2017) In Vivo Maturation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes in Neonatal and Adult Rat Hearts. Stem Cell Reports 8:278-289
Palpant, Nathan J; Wang, Yuliang; Hadland, Brandon et al. (2017) Chromatin and Transcriptional Analysis of Mesoderm Progenitor Cells Identifies HOPX as a Regulator of Primitive Hematopoiesis. Cell Rep 20:1597-1608
Yang, Xiulan; Murry, Charles E (2017) One Stride Forward: Maturation and Scalable Production of Engineered Human Myocardium. Circulation 135:1848-1850
Ruan, Jia-Ling; Tulloch, Nathaniel L; Razumova, Maria V et al. (2016) Mechanical Stress Conditioning and Electrical Stimulation Promote Contractility and Force Maturation of Induced Pluripotent Stem Cell-Derived Human Cardiac Tissue. Circulation 134:1557-1567
Roberts, Meredith A; Tran, Dominic; Coulombe, Kareen L K et al. (2016) Stromal Cells in Dense Collagen Promote Cardiomyocyte and Microvascular Patterning in Engineered Human Heart Tissue. Tissue Eng Part A 22:633-44
Qin, Wan; Roberts, Meredith A; Qi, Xiaoli et al. (2016) Depth-resolved 3D visualization of coronary microvasculature with optical microangiography. Phys Med Biol 61:7536-7550
Kolwicz Jr, Stephen C; Odom, Guy L; Nowakowski, Sarah G et al. (2016) AAV6-mediated Cardiac-specific Overexpression of Ribonucleotide Reductase Enhances Myocardial Contractility. Mol Ther 24:240-250
Pioner, Josè Manuel; Racca, Alice W; Klaiman, Jordan M et al. (2016) Isolation and Mechanical Measurements of Myofibrils from Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Stem Cell Reports 6:885-96
Hofsteen, Peter; Robitaille, Aaron M; Chapman, Daniel Patrick et al. (2016) Quantitative proteomics identify DAB2 as a cardiac developmental regulator that inhibits WNT/?-catenin signaling. Proc Natl Acad Sci U S A 113:1002-7

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