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Updated: Dec 25, 2025
Maturation of Human Stem Cell-derived Cardiomyocytes in Biowires Using Electrical Stimulation
Published on: May 6, 2017
Adrenoceptor Responses in Human Embryonic Stem Cell-Derived Cardiomyocytes: a Special Focus on Electrophysiological
Weiwei Jiang1, Xingjian Hu2, Fei Li1
1Departments of Cardiovascular Surgery (X.H., F.L., G.L., Y.W.) and Gastroenterology (W.J.), Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; and Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland (Y.W.).
Insights
Chronic beta-1 adrenergic receptor (β1-AR) stimulation accelerates conduction velocity in human embryonic stem cell-derived cardiomyocytes (hESC-CMs) by upregulating Connexin 43. This study reveals a key pathway for adrenergic receptor regulation in hESC-CMs.
Area of Science:
- Cardiovascular Research
- Stem Cell Biology
- Electrophysiology
Background:
- Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) are a promising model for cardiovascular research.
- Electrophysiological responses of hESC-CMs to adrenergic receptor (AR) activation are not well understood.
- Understanding these responses is crucial for their application in disease modeling and drug screening.
Purpose of the Study:
- To characterize the electrophysiological response of hESC-CMs to adrenergic stimulation.
- To investigate the effects of AR activation on conduction velocity (CV) and action potential (AP) shape.
- To elucidate the underlying molecular mechanisms, including ion channel and connexin expression.
Main Methods:
- H9 hESC-CMs were differentiated and cultured to form confluent monolayers.
- Optical mapping was used to record AP shape and CV during pharmacological stimulation.
- Quantitative real-time PCR and Western blot analyzed gene and protein expression of connexins and ion channels.
Main Results:
- Chronic β-AR stimulation (24 hours) significantly increased CV by ~50% in hESC-CM monolayers.
- This effect was mediated by β1-AR, not β2-AR, and involved upregulation of Connexin 43 (Cx43) and Nav1.5.
- The CV acceleration and Cx43 upregulation were dependent on protein kinase A (PKA) and MAPK/MEK/ERK signaling pathways.
Conclusions:
- Chronic β1-AR stimulation accelerates CV in hESC-CMs primarily by upregulating Cx43 via the PKA/MEK/MAPK pathway.
- AP shape was less affected by AR stimulation compared to CV.
- These findings provide critical insights into the electrophysiological regulation of hESC-CMs by adrenergic signaling.
Abstract:
Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) have become a promising cell source for cardiovascular research. The electrophysiological characteristic of hESC-CMs has been generally studied, but little is known about electrophysiological response to adrenergic receptor (AR) activation. This study aims to characterize electrophysiological response of hESC-CMs to adrenergic stimulation in terms of the conduction velocity (CV) and action potential (AP) shape. The H9 hESC-CMs were acquired by a classic differentiation protocol and cultured to achieve confluent cell monolayers. The AP shape and CV among the monolayers were recorded using optical mapping during electrophysiological and pharmacological stimulation experiments. Quantitative real-time polymerase chain reaction and Western blot were adopted to determine the expression levels of Connexin and ion channel gene and protein. Chronic β-AR stimulation by isoproterenol for 24 hours in hESC-CM monolayers increased CV by approximately 50%, whereas α-AR or acute β-AR stimulation had no significant effect; chronic β-AR stimulation resulted in a significant Connexin (Cx) 43 and Nav1.5 upregulation at both protein and mRNA level. Isoproterenol-induced CV accelerating and Cx43 and Nav1.5 upregulation in hESC-CMs, which was attenuated by selective β1-adrenoceptor antagonist CGP 20712A but not selective β2-antagonist ICI 118551. Moreover, pretreatment with protein kinase A (PKA) inhibitor H89, mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (MEK) inhibitor SB203580, and MAPK inhibitor PD98059 suppressed the isoproterenol-induced CV accelerating and Cx43 upregulation, whereas it had no significant effect on Nav1.5 upregulation. The AP shape in hESC-CM monolayers was less susceptible by either β-AR or α-AR stimulation. It was β1-AR not β2-AR contributing to the modification of conduction velocity among hESC-CM monolayers. Chronic β1-AR stimulation accelerates CV by upregulating Cx43 via PKA/MEK/MAPK pathway. SIGNIFICANCE STATEMENT: These data provide new insight into the electrophysiological characteristics of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and depict a concise signaling pathway in the adrenergic receptor (AR) regulation of action potential shape and electrical propagation across hESC-CM monolayer. It is β1-AR not β2-AR contributing to the modification of conduction velocity in hESC-CMs and accelerating conduction velocity by upregulating Connexin 43 via protein kinase A/ mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase/MAPK pathway.
