A critical role of retinoic acid concentration for the induction of a fully human-like atrial action potential phenotype in hiPSC-CM

Summary

Retinoic acid (RA) induces an atrial phenotype in human induced pluripotent stem cells (hiPSCs), but expression of atrium-selective currents such as the ultrarapid (IKur) and acetylcholine-stimulated K+ current is variable and less than in the adult human atrium. We suspected methodological issues and systematically investigated the concentration dependency of RA. RA treatment increased IKur concentration dependently from 1.1 ± 0.54 pA/pF (0 RA) to 3.8 ± 1.1, 5.8 ± 2.5, and 12.2 ± 4.3 at 0.01, 0.1, and 1 μM, respectively. Only 1 μM RA induced enough IKur to fully reproduce human atrial action potential (AP) shape and a robust shortening of APs upon carbachol. We found that sterile filtration caused substantial loss of RA. We conclude that 1 μM RA seems to be necessary and sufficient to induce a full atrial AP shape in hiPSC-CM in EHT format. RA concentrations are prone to methodological issues and may profoundly impact the success of atrial differentiation. Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.

Authors Schulz C, Sönmez M, Krause J, Schwedhelm E, Bangfen P, Alihodzic D, Hansen A, Eschenhagen T, Christ T
Journal Stem cell reports
Publication Date 2023 Nov 14;18(11):2096-2107
PubMed 37922915
PubMed Central PMC10679650
DOI 10.1016/j.stemcr.2023.10.006

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