Metabolic Maturation Media Improve Physiological Function of Human iPSC-Derived Cardiomyocytes

Abstract

SUMMARY Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) have enormous potential for the study of human cardiac disorders. However, their physiological immaturity severely limits their utility as a model system and their adoption for drug discovery. Here, we describe maturation media designed to provide oxidative substrates adapted to the metabolic needs of human iPSC (hiPSC)-CMs. Compared with conventionally cultured hiPSC-CMs, metabolically matured hiPSC-CMs contract with greater force and show an increased reliance on cardiac sodium (Na + ) channels and sarcoplasmic reticulum calcium (Ca 2+ ) cycling. The media enhance the function, long-term survival, and sarcomere structures in engineered heart tissues. Use of the maturation media made it possible to reliably model two genetic cardiac diseases: long QT syndrome type 3 due to a mutation in the cardiac Na + channel SCN5A and dilated cardiomyopathy due to a mutation in the RNA splicing factor RBM20. The maturation media should increase the fidelity of hiPSC-CMs as disease models.

Metabolically-Driven Maturation of hiPSC-Cell Derived Cardiac Chip

“…Altogether, these experimental results are consistent with the prediction of the simulations that pre-treatment with MM increases the SR Ca 2+ store, and its contribution to the cytosolic Ca 2+ transient that fuels contraction. These results are internally consistent with the results of our simulations, and with previous work where matured hiPSC-CM exhibited a more marked calcium decay time in response to thapsigargin 36 . In previous studies, maturation media containing dexamethasone and triiodothyronine 66 , and maturation induced by continuous field pacing 23 have been linked to improvements in hiPSC-CM Ca 2+ handling through formation of T-tubules.…”

“…Strikingly, this media had opposing effects on the action potential duration of genetically unique hiPSCderived tissue chips, with the net result of forcing both genotypes towards an actional potential duration range that is typical for adult human ventricular cardiomyocytes. These results suggest that, as in monolayer culture of hiPSC-CM 36 , maturation with fatty-acid based media may be a prerequisite to using hiPSC-CM based tissue chips to predict how drugs will affect the adult human heart.…”

“…Postnatally, the heart switches from glycolysis to fatty-acid oxidation as its primary source of ATP 31,32 . Previously, 2D hiPSC-CM monolayers and engineered tissues exposed to glucose-depleted, fatty-acid enriched media exhibited more mature metabolic profiles and physiology compared to hiPSC-CM cultured in standard media [33][34][35][36] . However, fattyacid based media has not been studied in the context of MPS, and potential population variance in cellular response to fatty-acid media has not been explored.…”

Reorganization of Metabolism during Cardiomyogenesis Implies Time-Specific Signaling Pathway Regulation

“…It was shown that high glucose concentrations can reduce mitochondrial function [ 16 ], while excluding glucose from the medium favors the metabolic switch to mitochondrial oxidative phosphorylation [ 13 , 17 ]. Also, Feyen and collaborators demonstrated that the inclusion of oxidative substrates to the culture medium of iPSCs-CM produce metabolically mature CMs, improving electrophysiological and mechanical parameters [ 18 ].…”

Building Multi-Dimensional Induced Pluripotent Stem Cells-Based Model Platforms to Assess Cardiotoxicity in Cancer Therapies

“…Unlike adult cardiomyocytes, neonatal or iPSC cardiomyocytes do not show rectangular morphology, exhibit spontaneous generation of AP, have lower density of mitochondria and higher dependence on glycolytic metabolism over fatty acid oxidation. Several recently developed techniques help iPSC-CM maturation through metabolic supplementation ( Parikh et al, 2017 ; Feyen et al, 2020 ), incremental pacing ( Chan et al, 2013 ) and culture substrate modifications to promote higher contraction forces ( Pandey et al, 2018 ). Currently, these culture procedures from somatic reprogramming to obtaining functionally mature iPSC-CMs require over a month’s time, which may limit their use for point-of-care testing.…”