Abstract 15150: Triidothyronine and Dexamethasone Improve Electrophysiological Maturation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes
Introduction: Although human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are increasingly used for disease modeling, a major limitation are their relative electrophysiological immaturity (i.e., spontaneous electrical activity, low levels of inward rectifier current (IK1), and high levels of pacemaker current (If)). Triiodothyronine (T3) plays an important role for heart development and combined with Dexamethasone has been reported to improve functional properties of hiPSC-CMs but its effect on IK1 and If is unknown.
Objective: To test whether addition of T3 & Dexamethasone to standard hiPSC cardiac induction media enhances electrophysiological maturation of hiPSC-CM without increasing culturing time.
Methods: T3 & Dexamethasone or vehicle was added to cardiac induction media from day 16 to day 30. Day 30th hiPSC-CMs were dissociated, plated at single cell density for 5 days on a flexible matrigel substrate and studied using voltage clamp and confocal imaging.
Results: Spontaneous beating rate was significantly reduced in hormone-treated compared to vehicle-treated hiPSC-CM (10±1.7 b/min vs. 23±1.9 b/min, n=10, p<0.01). Consistent with the reduced beating rate, If density was three-fold decreased by hormone treatment (-2.7±0.35 pA/pF vs. -6.2±1.3 pA/pF at -120 mV, n=6, p<0.05). As shown in the Figure, IK1 density was four-time higher in hormone-treated hiPSC-CM than in control (-19.3±2.2 pA/pF vs. -4.4±0.5 pA/pF at -120 mV, n=7, p<0.01). In addition to the electrophysiological maturation, hormone-treated hiPSC-CM exhibited more organized Ca release and early t-tubule development.
Conclusion: Addition of T3 & Dexamethasone to standard protocols may be an effective approach for rapidly enhancing electrophysiological and ultrastructural maturity of hiPSC-CMs.
Author Disclosures: L. Wang: None. S. Parikh: None. M. Gomez-Hurtado: None. K. Kim: None. B. Knollmann: None.
- © 2016 by American Heart Association, Inc.