Introduction:
The limited success of pharmacological approaches to atrial fibrillation (
AF
) is due to limitations of
in vitro
and
in vivo
models and inaccessibility of human atrial tissue. Patient-specific induced pluripotent stem cell-derived atrial cardiomyocytes (iPSC-aCMs) are a robust platform to model the heterogeneous myocardial substrate of AF, but their immaturity limits their fidelity.
Objective:
We hypothesized that a combinatorial approach of biochemical (triiodothyronine [
T3
], insulin-like growth factor-1 [
IGF-1
], and dexamethasone; collectively
TID
), bioenergetic (fatty acids [
FA
]), and electrical stimulation (
ES
) will enhance electrophysiological (
EP
), structural, and metabolic maturity of iPSC-
a
CMs.
Methods:
We assessed maturation with whole cell patch clamping, calcium transients, immunofluorescence (IF), Seahorse Analyzer, contractility assay, RT-PCR, Western Blotting, and RNA sequencing (RNAseq). Using a time series with RNAseq we identified signaling pathways and transcriptional regulation that drive EP, structural, and metabolic atrial development and compared iPSC-aCM maturity with human aCMs (haCMs) obtained from the same patient.
Results:
TID+FA+ES significantly improved structural organization and cell morphology (
Fig. 1a
), enhanced membrane potential stability and improved depolarization (
Fig. 1b
), improved Ca
2+
kinetics with faster and increased Ca
2+
release from sarcoplasmic reticulum (
Fig. 1c
), and increased expression of Na
+
, Ca
2+
, and K
+
channels, markers of structural maturity, FA metabolism, and oxidative phosphorylation (
Fig. 1d
). There was no difference in each parameter between TID+FA+ES iPSC-aCMs and haCMs from the same patient.
Conclusion:
Our optimized, combinatorial TID+FA+ES approach markedly enhanced EP, structural, and metabolic maturity of human iPSC-aCMs, which will be useful for elucidating the genetic basis of AF developing precision drug therapies.
Acquisition of chromosome 1q duplication in parental and genome‐edited human‐induced pluripotent stem cell‐derived neural stem cells results in their higher proliferation rate in vitro and in vivo