Pluripotent Stem Cell Derived Cardiac Cells for Myocardial Repair

Summary

We present three novel and more efficient protocols for differentiating human induced pluripotent stem cells into cardiomyocytes, endothelial cells, and smooth muscle cells and a delivery method that improves the engraftment of transplanted cells by combining cell injection with patch-mediated cytokine delivery.

Abstract

Human induced pluripotent stem cells (hiPSCs) must be fully differentiated into specific cell types before administration, but conventional protocols for differentiating hiPSCs into cardiomyocytes (hiPSC-CMs), endothelial cells (hiPSC-ECs), and smooth muscle cells (SMCs) are often limited by low yield, purity, and/or poor phenotypic stability. Here, we present novel protocols for generating hiPSC-CMs, -ECs, and -SMCs that are substantially more efficient than conventional methods, as well as a method for combining cell injection with a cytokine-containing patch created over the site of administration. The patch improves both the retention of the injected cells, by sealing the needle track to prevent the cells from being squeezed out of the myocardium, and cell survival, by releasing insulin-like growth factor (IGF) over an extended period. In a swine model of myocardial ischemia-reperfusion injury, the rate of engraftment was more than two-fold greater when the cells were administered with the cytokine-containing patch comparing to the cells without patch, and treatment with both the cells and the patch, but not with the cells alone, was associated with significant improvements in cardiac function and infarct size.

Introduction

Human induced pluripotent stem cells (hiPSCs) are among the most promising agents for regenerative cell therapy because they can be differentiated into a potentially unlimited range and quantity of cells that are not rejected by the patient's immune system. However, their capacity for self-replication and differentiation can also lead to tumor formation and, consequently, hiPSCs need to be fully differentiated into specific cell types, such as cardiomyocytes (CMs), endothelial cells (ECs), and smooth muscle cells (SMCs), before administration. One of the simplest and most common methods of cell administration is direct intramyocardial injection, but the number of ....

Protocol

All experimental procedures are performed in accordance with the Animal Guidelines of the University of Alabama at Birmingham.

1. Differentiating hiPSCs into hiPSC-CMs

1. Coat the wells of a 6-well plate with pre-cooled growth-factor-reduced gelatinous protein mixture at 4 °C for overnight. Aspirate the gelatinous protein mixture before use. Seed the hiPSCs onto the pre-coated plates, and culture the cells (1 x 10⁵ cell per well) at 5% CO₂ and 37 °C in mTeSR1 medium supplement with 10 µM ROCK inhibitor.
2. Refresh the medium daily until the cells reach 90% confluence; then, add growth-fac....

Results

Characterization of Differentiated hiPSC-CMs, -ECs, and -SMCs

The differential capacity of hiPSCs were evaluated^2,3,4. Flow cytometry analyses of cardiac troponin T (cTnT) expression suggest that the purity of the final hiPSC-CM population can exceed 90% (Figure 1A, 1B, panel B1). Nearly all of the cells e.......

Discussion

Improved Yield/Purity of hiPSC-CMs

Conventional protocols for differentiating human stem cells into CMs are often limited by low yield and purity; for example, just 35-66% of hESC-CMs obtained via Percoll separation and cardiac body formation expressed slow myosin heavy chain or cTnT⁶. The purity of differentiated hiPSC-CM populations can be substantially increased by selecting for the expression of a reporter gene that has been linked to the promoter of a CM-specific prot.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Protocol Section 1
mTeSR1 medium	Stem cell technologies	5850
Growth-factor-reduced matrigel	Corning lifescience	356231
Y-27632	Stem cell technologies	72304
B27 supplement, serum free	Fisher Scientific	17504044
RPMI1640	Fisher Scientific	11875-119
Activin A	R&D	338-AC-010
BMP-4	R&D	314-BP-010
bFGF	R&D	232-FA-025
Collagenase IV	Fisher Scientific	NC0217889
Hanks Balanced Salt Solution (Dextrose, KCl, KH2PO4, NaHCO3, NaCl, Na2HPO4 anhydrous)	Fisher Scientific	14175079
Fetal Bovine Serum	Fisher Scientific	10438018
6-well plate	Corning Lifescience	356721
10 cm dish	Corning Lifescience	354732
Cell incubator	Panasonic	MCO-18AC
Protocol Section 2
Versene	Fisher Scientific	15040066
Fibrinogen	Sigma-Aldrich	F8630-5g
Thrombin	Sigma-Aldrich	T7009-1KU
EMB2 medium	Lonza	CC-3156
VEGF	ProSpec-Tany	CYT-241
EPO	Life Technologies	PHC9431
TGF-β	Peprotech	100-21C
EGM2-MV medium	Lonza	CC-4147
SB-431542	Selleckchem	S1067
CD31	BD Bioscience	BDB555445
CD144	BD Bioscience	560411
15 ml centrifuge tube	Fisher Scientific	12565269
Eppendorff Centrifuge	Eppendorf	5702R
Protocol Section 3
CHIR99021	Stem cell technologies	720542
PDGF-β	Prospec	CYT-501-10ug
Protocol Section 4
Olive oil	Sigma-Aldrich	O1514
Gelatin	Sigma-Aldrich	G9391
Acetone	Sigma-Aldrich	179124
Ethanol	Fisher Scientific	BP2818100
Glutaraldehyde	Sigma-Aldrich	G5882
Glycine	Sigma-Aldrich	G8898
IGF	R&D	291-G1-01M
Bovine serum albumin	Fisher Scientific	15561020
Heating plate	Fisher Scientific	SP88850200
Water bath	Fisher Scientific	15-462-10Q
Protocol Section 5
CaCl2	Sigma-Aldrich	223506
ε-aminocaproic acid	Sigma-Aldrich	A0420000
MEM medium	Fisher Scientific	12561-056
Syringe	Fisher Scientific	1482748
Anesthesia ventilator	Datex-Ohmeda	47810
Anesthesia ventilator	Ohio Medical	V5A
Defibrillator	Physiol Control	LIFEPAK 15
1.5 T MRI	General Electric	Signa Horizon LX
7 T MRI	Siemens	10018532
Gadolinium Contrast Medium (Magnevist)	Berlex	50419-188-02
2-0 silk suture	Ethilon	685H
3-0 silk suture	Ethilon	622H
3-0 monofilament suture	Ethilon	627H