Journal
CIRCULATION RESEARCH
Volume 121, Issue 12, Pages 1323-+Publisher
LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1161/CIRCRESAHA.117.311920
Keywords
calcium; cardiac electrophysiology; extracellular matrix; stem cells
Funding
- US National Institutes of Health [R01HL71670, R01HL128044, R01HL124935, P50GM115305, U01HL131911]
- National Institute of General Medical Sciences [T32 GM07347, T32 GM07628]
- National Heart, Lung, and Blood Institute [F30 HL131179]
- Imaging through Vanderbilt University Medical Center Cell Imaging Shared Resource
- European Union [647714]
- [T32 NS 007491]
Ask authors/readers for more resources
Rationale: Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are increasingly being used for modeling heart disease and are under development for regeneration of the injured heart. However, incomplete structural and functional maturation of hiPSC-CM, including lack of T-tubules, immature excitation-contraction coupling, and inefficient Ca-induced Ca release remain major limitations. Objective: Thyroid and glucocorticoid hormones are critical for heart maturation. We hypothesized that their addition to standard protocols would promote T-tubule development and mature excitation-contraction coupling of hiPSC-CM when cultured on extracellular matrix with physiological stiffness (Matrigel mattress). Methods and Results: hiPSC-CM were generated using a standard chemical differentiation method supplemented with T3 (triiodothyronine) and/or Dex (dexamethasone) during days 16 to 30 followed by single-cell culture for 5 days on Matrigel mattress. hiPSC-CM treated with T3+Dex, but not with either T3 or Dex alone, developed an extensive T-tubule network. Notably, Matrigel mattress was necessary for T-tubule formation. Compared with adult human ventricular cardiomyocytes, T-tubules in T3+Dex-treated hiPSC-CM were less organized and had more longitudinal elements. Confocal line scans demonstrated spatially and temporally uniform Ca release that is characteristic of excitation-contraction coupling in the heart ventricle. T3+Dex enhanced elementary Ca release measured by Ca sparks and promoted RyR2 (ryanodine receptor) structural organization. Simultaneous measurements of L-type Ca current and intracellular Ca release confirmed enhanced functional coupling between L-type Ca channels and RyR2 in T3+Dex-treated cells. Conclusions: Our results suggest a permissive role of combined thyroid and glucocorticoid hormones during the cardiac differentiation process, which when coupled with further maturation on Matrigel mattress, is sufficient for T-tubule development, enhanced Ca-induced Ca release, and more ventricular-like excitation-contraction coupling. This new hormone maturation method could advance the use of hiPSC-CM for disease modeling and cell-based therapy.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available